Google Plus now has 20m+ users and a the press can't get enough of it. The obvious question is what does engagement look like both near and long-term. One indicator is referral traffic. So here is a look at referrals to Obviously it not the ideal example - but content is shared equally across Facebook, Twitter and Google Plus. So it is fair... Here are two charts of the top referring sites.

First, for all of July (note that Google Plus was days old on July 1):

Google Plus still trails Facebook and Twitter. Google Plus represents about 55% of Twitter's referrals... to put that in perspective, I have ~5x the followers on Twitter than I do on Google Plus. Clearly there is a higher engagement ration there.

The last week (Google Plus now more open & popular):

Over the last week Google Plus is the #3 referring site and ahead of Twitter and Facebook. Clearly this is imperfect data since Facebook and Twitter shifted markedly over the month (historically they are about even) but it is impressive that:

1. Google Plus is making a significant contribution just a couple weeks into launch 2. Google plays such a meaningful in referral traffic: Google, SEO, SEM, Plus, etc.

Of course this has real implications for marketers & brands and how they should think about leveraging / interacting on Google Plus. Furthermore, it is a powerful position for Google (should the trend continue) because they can begin connecting the properties (SEO, SEM, Plus, .com)... which in turn will cause marketers (and their budgets) to dedicate themselves further to Google.