Couple of SE usage statistics requests.

I can't find a good source!

[Miter]

Does anyone know of a reputable site or two that list stats such as:

"Search engine users are ___times more likely to click on an organic link than a paid ad"

and/or

"___% of users are likely to abandon a search after the first ___ (three?) pages"

I'd also be interested in stats relating to the boom in SEO/SEM services being requested. :)

Thanks in advance!

[Xandada]

Internet retailer is an online mag that has these types of stats