I’ve been subscribed to HARO for awhile now. I got one of my projects featured in a blog about writing and I made a contact that may result in some press around February. It is the real deal.
Oh I’ve also referred several reporters to friends of mine. So its good for karma too.
Rishi is right though, it takes time to go through all the queries each day. Several times I’ve pondered writing software to help “smartly” filter this (meager AI background on my part).