I use Flickr, but none of my friends who aren't photographers do... so when I update my stream nobody sees it (unless I use a Flickr-Facebook bridge app, which is clunky and doesn't plug in nicely).

There's a lot to be said for having your content pushed to your network in a way that's easy to use.

In fact, Buzz's integration of "external feeds" is much better done than FB. I'd hope this applies to Google+ also.