Speaking about the need to own the entire consumer journey- Conversion Optimizer is an attempt by Google to integrate with advertisers to gain conversion data. It also helps advertisers more efficiently spend their advertising dollars by automatically adjusting their CPC bids based on conversion history.
The more data Google has on conversions the better they could make ALL of their ad products. Today they live and die by the click, but that’s bound to change someday. This is an important feature that could add value to their core business – advertising.