Why Did Google Buy Waze?

Today Google bought Waze, a navigation program, for $1.3 billion. The question is why did they do it? Well I have two reasons why they would pay so much for a foreign company.
1.  To keep Facebook from getting their hands on it.
2.  To incorporate the real time traffic technology that It uses.
I feel that the main reason was reason number one. I feel this way because if google could get their mapping and navigation systems to be the best in the world, thats just another area they will dominate. But I can also see reason number two having to do with the decision to. Google might just be trying to keep Facebook from getting something that Google doesn’t have. But it happened and now google plans to keep Waze in Isreal for the next three years. After that they will more than likely get rid of the company and use the technology in google maps to give better traffic updates.