I'm too cheap to make a cash contribution, but I do feel some obligation to "pay my way" somehow. Everything costs somebody something, right? As your post points out, this IS somebody's way of making a living, after all....by way of advertising revenues, I think.
With that in mind, I don't block the ads, and make it my business to even click on a fair number of them. (I think that the more clicks that come from the site, the more revenue. Or that's my theory, anyway.)
It doesn't seem to make my spamfile fill up, and even if it did, who cares? Let 'em crawl up my leg all they want- Wild Horses couldn't make me actually buy
The only down side to this approach has been that lately there's an ad that's starting to bug me some: it's for a T-shirt company that features whatchamightcall a Blonde Cupcake wearing not-quite-enough t-shirt, if you know what I mean...
She seems to be following me around from thread to thread, and it's getting a little annoying. If there's a way to replace her in the ad with a "Mr. Beefcake", I'd sure like to hear about it!