Yesterday Google tricked out its Google Shopping options by bringing its formerly tablet-only Google Catalogs to the web. It’s an expansion of the free iPad and Android app Google introduced last August that let you create collages of items you liked, find a nearby store, or go to the merchant’s website to purchase an item–essentially, everything but make in-app purchases.





The web version of Google Catalogs will still direct you to featured merchants’ own websites, but Google says in the future it will “incorporate catalogs more deeply throughout the Google Shopping experience, giving you more ways to find ideas and inspiration as you shop and engage with your favorite brands.”

Google could be gearing up for an interesting play against Amazon and eBay with Google Shopping by pivoting itself from its role as the middleman–between the consumer on one end and the Amazons and eBays on the other–to the actual shopping destination.

It may be a bit of a stretch to infer that from a simple update to Catalogs, but it makes sense when you consider other recent moves Google has made in its approach to e-commerce. In May, Google that Google Product Search, which was free for merchants to list products, would become Google Shopping and switch to a paid inclusion model. Starting this month, any vendor who wants their listings to show up specifically within Google Shopping results will have to pay to do so. The idea is that if you’re a merchant who’s paying for listings, you’re that much more likely to be trustworthy.

Google has also been trying to beef up quality assurance for the merchants it lists, similar to how Amazon ensures the safety of buying from sellers on Amazon Marketplace, through measures such as “Trusted Stores,” which stamps those that pass muster with a Google stamp of approval.

The last piece of the puzzle is that Google already has its own payments system in Google Wallet, which, if integrated with a future version of Google Shopping that could let you make same-window purchases online and in-app purchases on your tablet, would give Amazon and eBay a great reason to worry.

All of which can make you start to think: What if the world’s biggest search engine created the world’s biggest shopping mall?