I've been aiming to make my site as fast as possible. At first, I had successfully done that and firebug gave me a 99/100 page speed rank. Google Webmasters even pointed out that my blog was 82% faster than most websites ... until now. I have added Google Adsense to my blog, and they don't do much to at least try to speed up your site. They load ads from multiple javascript files when really they should combine it as one (I see 4 files for just one 200x200 banner ad). Which also brings me to Google Analytics which also does the same thing and lowers your site score. Before, I had a page speed rank of 99/100 (as stated above) and with one google ad, it drops to 93/100. Oh and Google Webmasters now reports that my site is 55% slower of most websites. (It was 82% faster...). I just don't see how a google ad can change it so much. It's nothing I can control really, but it is pretty annoying due to the fact they have the need site speed factor for SERP. Comments? Thoughts? Please let me know.
actually i'm also wondering about this.. one of my site is evn slower than yours.. although i implemented some caching system, still, it seems that my site is still slow as reflected on the google webmaster tool..
don't worry about that, external js's suchs as adsense, analytics and others, will only slow your website a bit..that doesn't mean that Google will penalize it or look to it differently now, don't worry
Google has over 100 algorithms to rank a website in search results page! And one such is the site speed factor! So think about the basic factors that ranks in search results - relevance and popularity! If you are already working on these, get your visitors feedback on your sites loading and do changes accordingly !
I think/hope Google would still do something about adsense/analytics in the end, since they are the one that is really promoting site speed, it doesn't make them look good if their own products are slowing down all the websites that use them.
I have noticed this too, and it was kind of annoying. However, I believe that site speed is a VERY small percentage of their 200+ factors. I remember watching a video where Matt Cutts said that it was only affecting the ranking of maybe 2-3% of websites. To me, this means that they are only using this as a negative factor. Meaning that if your site ranks 20/100 on the scale then you will be dinged, but it doesn't mean that your rank will improve if you go from 80 to 99/100. Does that make sense?