porivo - is it for real?

A friend of mine regularly sends me invitations to join the Porivo peer site. I can supposedly make money by doing so. My nature is rather skeptical, so I haven’t joined yet, but he keeps asking me to.

Anyone familiar with any drawbacks? Is there adware or spyware included? Other security risks to my machine?

What is it? - if it’s one of these ‘get paid to surf the net’ things then it’s a scam (ar as good as one; I don’t know of anyone who has come out of those in profit, except the organisers).

I’m not trying to promote it, since I don’t know enough about it, but the link is:

http://www.porivo.com/peernetwork/jsp/index.jsp

Doing a basic search on Google I couldn’t find any objective sites or articles discussing its virtues.

It looks like a fairly standard ‘get paid to surf and make $$$’ setup - not a scam as such, but might just as well be; you won’t make a fortune.