Adblock Plus and (a little) more

Extension update patterns · 2009-05-06 15:36 by Wladimir Palant

I recently released Adblock Plus 1.0.2 to fix a regression that would affect any user upgrading to Firefox 3.0.9. In the end, Adblock Plus upgrade was released only six days before Firefox 3.0.9 and the big question is of course — was that enough time? How many users ended up using the new Firefox release with an outdated Adblock Plus version?

Unfortunately, AMO statistics don’t allow correlating add-on versions with application versions so any estimates will require a fair amount of guessing. Also, AMO will show only absolute active daily users numbers which are hard to interpret due to strong day-to-day variation. I am more interested in “what percentage of my users upgraded on day X?” So I used gnuplot with AMO data to create a more useful graph:

Usage share for different Adblock Plus versions

Important findings:

  • 45% of the users upgrade within 3 days of the release. After that the upgrade rate slows down considerably, it seems that it takes around two months to upgrade 85% of the users.
  • There is still a considerable number of users with Adblock Plus 1.0 (newer version arrived four months ago) and even Adblock Plus (newer version arrived five months ago), that percentage barely gets smaller. So it seems that 10% of the users have extension updates enabled (they wouldn’t show up in the statistic otherwise) but ignore updates and will only update when they install a new major Firefox version because the old extension version will no longer be compatible then.
  • Firefox releases have a negligible effect on extension updates. This one came as a surprise given that the download numbers increase every time a new Firefox release comes out. However, the two bumps from Firefox 3.0.9 and Firefox 3.0.10 releases are barely noticeable and don’t seem to have any real effect whatsoever.

And what about the Firefox versions used by Adblock Plus users? Here comes another graph for the same period of time:

Usage share of different Firefox versions after Adblock Plus release

Important findings:

  • Adblock Plus users upgrade Firefox considerably faster than they upgrade Adblock Plus. 60% of the users upgraded in the first three days, and Firefox 3.0.8 is used by only 6% of the users two weeks after a new version was released.
  • Right now, almost 80% of the Adblock Plus users already use Firefox 3.0.9 and Firefox 3.0.10. However, only 70% of them use the latest Adblock Plus version. This means that at least 10% of them experience a regression in Adblock Plus functionality. To prevent this, I should have released at least a month earlier (but the issue wasn’t even found at that time of course).
  • Interestingly, it doesn’t look like Adblock Plus users are more likely to install minor versions of Firefox than average Firefox users. According to a recent study, the percentage of Firefox users running the latest release never exceeds 85%. That’s almost the same percentage as what you see in the graph above. However, around Firefox 3 release I noticed that Adblock Plus users installed the new major release considerably faster than average Firefox users — apparently, add-on users are only early adopters when it comes to major releases.

Luckily for me, changes in minor Firefox releases that break extensions are very rare (as far as I remember, that’s the first one ever that affected Adblock Plus). But it does make me think what can be done to make sure users upgrade sooner in cases like this. What if I change the compatibility info for version 1.0.1 on AMO to mark it as not compatible with Firefox 3.0.9/3.0.10, will it eventually give users some useful notification if they have it installed in Firefox 3.0.9? I guess Adblock Plus will show up as incompatible next time they update Firefox — and Firefox will offer searching for updates.


Comment [12]

  1. Wladimir Palant · 2009-05-06 15:36 · #

    If you have anything to say about NoScript – feel free to do so in the forum ( No registration is required, just click “Post reply”. All off-topic comments have been moved there.

  2. LorenzoC · 2009-05-06 23:36 · #

    Back to the topic, I would leave things as they are now. People who do not update extensions either are unable or do not want to update, so I do not see the point in making things a little more annoying/pushing for all the others.
    Personally I use your development builds so I do not mind :)

    Reply from Wladimir Palant:

    The problem is not those who don’t update (nobody can help with that). It is that they will update eventually – but that will take a while because they don’t know that this particular update is important. And until then they experience broken functionality (element hiding doesn’t work), something that they might not even realize.

  3. Old Pultney · 2009-05-07 01:51 · #

    Back on topic, it seems a good idea to force an upgrade if the older versions are liable to be broken and/or provide a degraded quality of service; the older versions would clearly not be compatible with more recent releases of Firefox. Tentatively I’d therefore agree that an attempt to coerce users onto a more recent version is a valid idea. After all, aside from the reduced QoS for the end-user, receiving hundreds of E-mails/forum posts/blog posts about the broken functionality of old versions must become very tedious and repetitive for yourself and the other ABP luminaries.

    Was anything ever decided about offering an upgrade for users of the original (defunct) AdBlock extension? I know I was using the damn thing for well over a year before discovering ABP was completely different and wasn’t updating my installation of AdBlock!

    Reply from Wladimir Palant:

    No, users of old Adblock just have to find the update themselves. At some point I tried to “adopt” the MozDev project – but that was blocked by rue who suddenly came to live. Supposedly, he still had plans for the project (this was more than a year ago and the project is still dead). There was some AMO discussion around Firefox 3 release and I offered to write a fake update that would install Adblock Plus. But that didn’t go anywhere either and they simply bumped maxVersion (even though Adblock has issues with Firefox 3). In the end they just removed it from their database, probably along with other extensions that are not compatible with supported Firefox versions. That means that offering Adblock users an update is no longer an option. I hope that the ones still using it (should be very few by now) will move on once Firefox 3.5 is released.

  4. JFW · 2009-05-07 09:47 · #

    Never installing any Firefox updates won’t prevent me from using the browser as it was released. It’s my choice that my software will be less up to date, less secure, and missing new features. Regardless, Firefox shouldn’t completely stop working because I choose not to upgrade to the newest version. It should only force me to update when it’s no longer compatible with my OS due to changes/updates to the OS itself.

    ABP should act the same. It should continue to function as long as the software is compatible with the environment, in this case FF. Even if it’s not the newest/best version out there. The compatibility option should only be used if a FF update prevents the addon from functioning properly (like the changed/updated OS in the previous example).

    Reply from Wladimir Palant:

    I think you are missing the point. The problem is that old Adblock Plus versions just don’t work properly if you update Firefox. If you are using a newer Firefox version you should also update Adblock Plus. But many people apparently take much more time to update Adblock Plus than to update Firefox.

  5. JFW · 2009-05-07 17:27 · #

    My bad, I must have misread then. If the old version of ABP no longer work as advertised after upgrading Firefox, then using the compatibility option seems like a very good idea to me.

    My point was that it shouldn’t force users to upgrade simply because the old version isn’t as good as a newer version, but still working as initially adverstised.

  6. lone wanderer · 2009-05-07 19:24 · #

    What happens with Firefox 2.x users, when you “force” a update? Adblock Plus won’t work for them, too? Or is it possible to mark compatibility with 2.x+ AND 3.0.9+?

    (I don’t use Fx2 and I know that it is outdated. But there are still a lot of installations out there.)

    If this is no issue for you, then tag Adblock Plus as incompatible. The compatibility feature is supposed to be used for such cases.

    Reply from Wladimir Palant:

    Since I would change maxVersion to 3.0.8, this won’t affect Firefox 2 users in any way.

  7. Lyx · 2009-05-08 18:39 · #

    Well, I have no problem with notifying users of incompatibilities. I would however also like to point out that this is a topic which needs to be handled with care:

    - It should not be abused. If users get annoyed all the time for messages regarding trivial incompatibilities, then you will only encourage them to ignore incompatibility messages.

    - Same for, but with higher intensity, forced updates. If users extensions get DISABLED because of minor incompatibilities, then a significant amount of people will look into ways to disabled that (as did i: extension incompatibility blocking is disabled in my case, because the whole versioning system feels highly paranoid to me. I get incompatibility warnings all the time, not because of significant incompatibilities, but just because the app version exceeded the limit given in the extension.)

    - While on that topic – one problem with the firefox extension update system is that it only knows black and white. Either you MUST update, or there is no significant reason to update. There is no direct way to inform them about important updates without forcing them to do it – unless the user disables extension compatibility checking :-)

    - People who do neither upgrade firefox nor their extensions shouldn’t get annoyed with constant upgrade messages. App developers IMO often fail to see the big picture when it comes to updates – they see all the things which were “improved” or “fixed” in newer versions… and elegantly mask out all the things which changed, which may be disadvantageous to certain users. I for example am planning to – after fx 3.5 is released – only do minor firefox updates. So, i will not upgrade to future major firefox versions, because over the course of the years i’ve become dissatisfied with the direction in which mozilla is moving (but i also dont have an efficient alternative yet).

  8. Jdo · 2009-05-10 00:15 · #

    It seems to me that a Firefox update to X.Y should, prior to actually installing itself, check installed extensions for compatibility with X.Y. Those which are marked as “explicitly verified OK with X.Y” require no special handling. If there are some which haven’t been explicitly verified, a list of those should be presented to the user along with drop-down box options for how to handle each of them. As an example…

    What would you like to do with these extensions which haven’t been verified to be compatible with this Firefox update:

    Extension1 (no verified update available): |Keep Using It|V|
    Extension2 (no verified update available): |Disable It|V|
    Extension3 (no verified update available): |Uninstall It|V|

    Extension4 (verified update available): |Update It|V|
    Extension5 (verified update available): |Keep Using It|V|
    Extension6 (verified update available): |Disable It|V|
    Extension7 (verified update available): |Uninstall It|V|

    To be honest, I’m not sure whether the existing framework would support such a scheme.

    Reply from Wladimir Palant:

    Firefox update does present you a list of incompatible extensions (though it might not have the most up-to-date data on extension compatibility, checking that takes time). As to presenting users with alternatives – how is a user supposed to make an informed decision? What if keeping an incompatible extension makes Firefox unusable?

  9. Thinboy00 · 2009-05-27 23:55 · #

    I’ve experienced an incompatibility warning firsthand. What happens:
    1)Fx updates itself as normal
    2)When you start it, it checks your addons’ maxVersions
    3)It warns you where appropriate, offers to check for updates to the addons, and if necessary, disables any offending addons

    The problem, if I understand correctly, is that some people installed ABP when maxVersion was larger than it now should be, so they won’t get warned at all. I can’t think of any obvious solution, but in the future, you might be a little more careful with setting maxVersion.

  10. ugg shoes · 2009-09-03 11:09 · #

    according to the two graph, there are much differences between them

  11. replica jersey · 2009-09-03 15:06 · #

    The argument that content has to somehow be paid for otherwise it will cease to be created is the same argument used by Bill Gates in his open letter to the softwre community in the 80’s saying that unless people paid for software nobody would develop any. We now see his argument is wrong, in the same way that content creators somehow have a right to assault my eyeballs with rubbish so that they can make money as thier primary motivation

  12. mee · 2010-10-22 20:40 · #

    re #8 & reply#8

    the next upgrade of firefox ought rename the extensions “manager” to: extensions catalog. The toggle would be between a catalog of available extensions and catalog of locally installed extensions. They are after all essentially lists… mere lists.

    until an upgrade is forged to allow for extensions feature management

    With feature management it would be faster for developers to patch extension functionality with soon to be annihilated by mozilla extensions for extensions.

    A feature manager would kill the need for arbitrary max version speculation.

    users need no longer blow in the wind with older verions of firefox to maintain their respective desired feature-set.

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