The subject lines for new contact notifications have funny grammar. For example, today I received an email with the subject "You got 1 new contacts today." The "You got" sound funny on its own, and "contacts" should be singular (especially since 1 is probably the most common number of new contacts.
It also seems a little strange that I got contacts without taking any action. Should the be "contact requests" or "followers"?
Finally, it's my humble opinion that these messages should go out less often by default, maybe every week or so.
Great work on the contacts system -- these are minor issues and overall it's working quite well.