Google+ should do what a lot of social networks have done in the
  past: you can get extra features if you upload a picture of
  yourself with your user number somewhere on it. They could have
  multiple levels: Limited user (pseudonym user), regular user
  (like it is now - real name, any picture), and super-user (real
  name + verified self-pic). You can have the choice whether or
  not to publically *show* your selfpic with your user number -
  but it would be something they could do. (this will probably get
  a lot of ppl mad at the idea, who are fighting for
  semi-anonymity (which i don't have a problem with at all) - but
  it is something google could do as an alternative to wanting
  people to pay - or perhaps if you want an Ad-free google+ you
  can verify your identity. ('cause we know the ads will be
  comin')