netmeg - 2:06 pm on Aug 26, 2011 (gmt 0)

I don't think you can or should look at it as an either / or. If your content is shareable, you need to put the tools and the signals in place to make it easy to share everywhere someone would be likely to share it. I think that's what Google looks at - are people sharing your content across various networks and means? There's nothing so specific as a "tweet is better than a like"