Ads are definitely a huge problem, but it seems they are at least equally, perhaps even less of a contributor to bloat than the tons of off-the-shelf Javascript frameworks/libraries major websites throw in to perform analytics, or to implement stock features like user-comments, login, social-media stuff, etc.
I mean, just looking at the network resources for a fresh download of www.cnn.com, I see:
livefyre_base.js, 167KB - apparently some kind of user-comment library
cdn.optimizely.com/js/131788053.js, 93.2K - some library for user tracking/analytics or something,
controltag.js, 72K - something from a company called "Krux DMP" that seems to be yet more user analytics and tracking,
sdk.js, 61.9K - something from gigya.com, apparently some kind of login and user-preferences framework
jsmd.js, 87.5K - another analytics framework
... and various others.
I see a "pubads_impl_113.js" from doubleclick.net, which is obviously for ads, but if cnn.com is typical, then it seems that off-the-shelf Javascript frameworks for user analytics and other stock features like logins/social-media crap, etc., are just as big a factor in contributing to bloat as display ads.
Optimizely is A/B testing. It's not strictly analytics (in that it's not a Google Analytics replacement), but it re-implements some of that functionality for audience targeting.
Krux is an ad tracking service.
jsmd.js appears to be the homebrew analytics system of one of the media partners.
The actual web analytics being run on CNN is Adobe Analytics, which is actually fairly compact. The real problem is that every ad also includes its own analytics framework. Each of them often includes multiple frameworks, each of which tracks something different. E.g. one for demographic targeting, one for tracking across multiple ad networks, one to see if the user scrolled far enough to see the ad, and one to see if the ad loaded before the user closed the page or navigated away. It's a goddamn mess.
> Ads are definitely a huge problem, but it seems they are at least equally, perhaps even less of a contributor to bloat than the tons of off-the-shelf Javascript frameworks/libraries major websites throw in to perform analytics
If you look at how this works out when you reload such a page just once, you'll see that you're wrong. The frameworks are heavy, but they are cached and typically only contribute to parsing delays etc., but ads load every time you visit the page and often the JS involved isn't cached, nor minified/gzipped.
Try a "repeat view" with webpagetest.org, for example.
Been running with uMatrix for a few weeks now and it's crazy how much gets loaded on every website that isn't necessary for the actual page's functioning. Websites finally feel snappy again - it's the best extension I've ever used.
I mean, just looking at the network resources for a fresh download of www.cnn.com, I see:
livefyre_base.js, 167KB - apparently some kind of user-comment library
cdn.optimizely.com/js/131788053.js, 93.2K - some library for user tracking/analytics or something,
controltag.js, 72K - something from a company called "Krux DMP" that seems to be yet more user analytics and tracking,
sdk.js, 61.9K - something from gigya.com, apparently some kind of login and user-preferences framework
jsmd.js, 87.5K - another analytics framework
... and various others.
I see a "pubads_impl_113.js" from doubleclick.net, which is obviously for ads, but if cnn.com is typical, then it seems that off-the-shelf Javascript frameworks for user analytics and other stock features like logins/social-media crap, etc., are just as big a factor in contributing to bloat as display ads.