Ask HN: Press Release Distribution Sites

Does anyone have advice regarding using services such as 24-7pressrelease.com or PRWeb.com to send out press releases?

I understand it's not the best, not targeted, etc. But, in terms of quantity, it seems like it would get the Press release in front of many more eyeballs than I could do myself.

Anybody use these in the past and can offer their experience or recommend a service?

Thanks in advance!