I have found that it's not that big of an impact, I also run the Google adsense but have learned that they don't index your site from what I can tell, best way to tell is to use the
Online Users Mod and it will show you where your users are coming from in the Who's Online page. It's for version 6.4 but maybe you can get it to work for 6.2.3?
After adding Josh's mod my traffic sky rocketed and I am getting more people registering than ever now.
