Sgt_Kickaxe - 2:06 am on Jun 28, 2012 (gmt 0)

I removed adsense and analytics from a site completely, the results included:

- Page load speed was greatly improved, from 3 seconds down to 1.5 seconds.
- Page SEO improved greatly on all of the popular testing sites, a 100% score in most cases
- No immediate change but traffic ramped up 21% above what I expected over the next 5 weeks
- More engaged visitors
- Lower bounce rate

I'd say the ads do weigh down a site, especially when loaded with javascript from a 3rd party server, and that it impacts traffic/serps. Unfortunately removing them from all sites isn't an option for most.