I've had people ask in the past what I get out of all of this. I've answered to this in the forums a few times.
The answers may surprise you, but by far the best things are the emails I get to read each morning (especially the ones from people who've been putting up with scratched or broken glasses as a means of continuing to put food on the table) as I sit down a piping hot bowl of oatmeal.
Indeed there is a financial piece, but the "average rate" I've seen comes up far short of the hours I miss relaxing with the family in the evening. Suffice it to say, you could make *much* more asking people if they'd "like to supersize that". Essentially, a few of the retailers run affiliate programs like thousands of other retailers (Best Buy, Apple, Sears, Amazon...). It's an effective and efficient alternative to direct advertising which is difficult to guage. I receive a small percentage of some sales (which at these prices is usually a very small number).
The biggest benefit to these professional relationships, is that they're very interested in continuing them. To that end I'm able to call upon someone higher up in the food chain when something goes wrong with one of your orders. Comb the forums and comments -- I'm sure you'll see many notes to that effect.
I'm doing nothing revolutionary here. I'm passionate about the topic (the site wouldn't have made it over a year if I wasn't) and I continue to look out for and dig for deals for all of you!