Thinking about it, it makes sense for google though. Web scraping and data analysis is their forte. And it fits within google's approach of "answering any question someone has". If someone wants to know the cheapest place to get X, they just want someone to type X into google and get the best answer. For them it's not about making money on commission. Instead it's about getting buy-in into their ecosystem. Apparently they think they can provide a better experience than the commercial sites can.