People I Don't Know Inviting Me To Networks I Don't Need

I'm getting so many invites to so many little social networks by so many people I don't know it's not even funny.

Whether they're actual people building their personal networks or employees just trying to build the company doesn't really matter.

I rarely know them.  I've rarely heard of the sites.

I was checking out the sites themselves, typing in the url, bypassing the invite, but today I stopped doing that every time.

Are we reaching saturation on "invite a web friend that doesn't know you" as a tactic for building social networks?

I think so though if someone I do know writes me I will check out the site.

At this point for me it's all about LinkedIn, though I'm a passive user, and possibly about Xing, though I have yet to join.

So I'm obviously not part of the market for most of the networks contacting me.  This is more of a canary in the coal mine post but seeding social networks by sending out random invites seems pretty played out at this point.