If I were looking for a new startup job, I would check out Mattermark first to develop a list of startups I thought looked like they were doing financially well / had strong employee growth etc and could succeed before then looking into which I was interested in the work at. I think Mattermark could have some other uses for their data that could prove valuable (I'd pay for that).
Right now if I were in that situation, it looks like I could get a 30 day trial for free but I wouldn't continue it at $499 a month. I wonder what other monetization opportunities there are for the data Mattermark has.