Press release sites have always been so-so for me. I've used PR Newswire in the past and have had success with getting the release picked up. If it's a well-written press release with an interesting hook, you can definitely get traction. The question is what is the traction for and does it actually convert into sales.

So I'd say it depends on your goal – if all you care about is eyeballs and your press release is good, go for it. But make sure you've thought about how best you can spend your time/money to make sure there's not a better outbound approach you could be taking.