How does Google get its ideas ?

I just heard this podcast by Marissa Mayer (VP Search Products and User Experience @ Google) and she has the following to say on where Google gets its ideas.

Ideas come from everywhere , sometimes overall strategy, sometimes from acquisition, sometimes from the need or problem identified by their employees...million different places ideas come from, Google encourages ideas to easily flow, and there is a rating system which allows ideas to be ranked and the best ideas go on the top.

Overall talk is quite interesting on ideas and innovation.
Listen here.