[aragot]

I think the earthshaking point of the agreement is: Reputation.

With Twitter info, Google will be able to determine who are the leaders in the world. As the founder of a small, bootstrapped product, I know that my competitors are able to leverage way more followers because they're large service companies with small products. I've benefited from good rankings on Google due to several factors that didn't depend on the size of my audience, such as doing my Q&A in public (on Atlassian Answers). If Google leverages Twitter's social graph, it will probably give a preference to the pages of the bigger company with more followers.

Which is "a good thing" in the grand scheme of economics: People trust more the software of big companies than small ones, whether I like that or not.