Just read this piece that reminds me that not only does Google not allow posting from apps other than Google+, it also doesn't have feeds so there's no way to get your stuff out.
I don't know what they're doing at Google, but they're going the wrong way with this stuff.
My systems have feeds coming out and can be wired up to other systems to integrate their input.
We still have more work to do but everything is aimed toward being open pipes on both end.
Someday one of these companies will try to build a coral reef and will reap huge gains.