Because Google already owns your soul...

... they might as well have the rights to your face.

Google + members should check their updated terms of use agreement.  Google is going to start using your face and opinion to endorse products across the interweb.  Your permission is not really necessary, and besides you gave it them when you decided to use their products.

Read this article for more details:

http://www.cnn.com/2013/10/11/tech/social-media/google-plus-ads-profiles/index.html?hpt=hp_bn5


Next up, Google Life Management.  You, Only Better.