[petercooper]

As for Slashdot, I always sort of wondered whether or not the appeal to those advertisers was less clickthrough and more name recognition.

That has been cited by some advertisers, for sure - especially those who are recently funded or have larger branding budgets.

Take New Relic, for example. They're sponsoring The Ruby Show for I'd guess (and I don't know for sure, but basing on rates of similar podcasts) at least $300-$500 per show? There's no way they're getting that much business from people listening to the show checking them out at that very moment. In terms of brand awareness, though, $5-8k a year is nothing if almost every Ruby developer has at least heard of you..