ResearchGate: spam scam, or…?

I’ve been getting fairly regular automated emails lately from ResearchGate, which has pull-quotes from Forbes and NPR saying it’s changing the way we do research blah blah blah. However, all empirical reports I have heard indicate that once you join, it repeatedly spams all of your co-authors with requests to join, which makes it feel a bit more like Heaven’s Gate.

On a less grim note, the site’s promise to make your research “more visible” sounds a bit like SEO spam. Given the existence of Google Scholar, which is run by the SE that one would like to O, it seems slightly implausible.

Any readers want to weigh in on whether ResearchGate has been useful to them? Or is this mostly for people who don’t know how to make their own homepage with their papers on it (which is probably most faculty).