One of the biggest events in the comic book world has to be the race staged by the Flash and Superman around the world. While this comparison may have some scratching heads over just what this has to do with anything, a similar race in online shopping is actually brewing now between two equally potent titans of the Web: Amazon and Google. But this time the race around the world is focused squarely on the front doors of users everywhere.

While there's no doubt that Google is king of most searches, it has yet to be the official king of search thanks to one key deficiency: product searches. When it comes to actually searching for things people plan to buy, Google is not the first stop for many. Rather, Amazon steps in at this point, not only offering product searches but a means to quickly and easily buy the product in question. With Amazon delivering more products, and more types of products—grocery delivery is becoming a frequent part of the picture in some cities, and Amazon Prime Air may well change the face of delivery as we know it if the FAA can get some rules set up—Google's ability to provide product searches only diminishes.

But Google isn't taking this point lying down. Not only has Google brought out a few services geared toward becoming a one-stop shopping destination for users—including tools like Google Checkout, Google Wallet, and most recently Google Shopping Express—but now Google plans, according to reports, to commit as much as $500 million to ramp up Google Shopping Express on a nationwide basis.

With this kind of investment, Google has reportedly ramped up its marketing efforts in the areas where the service will be available, and picked up not only delivery vehicles, but also delivery personnel in a bid to get the goods where said goods need to be. But Google also has another unexpected difference that may actually help it compete. While Amazon maintains stock in warehouses, as well as connects suppliers of used goods in some degree, Google instead essentially operates as a personal shopper. Google takes users' orders, at last report, and picks up said items at area retailers, and then brings said items to the user's door. That's making Google essentially an ally to the local businessman, facilitating the existence of the brick-and-mortar operation rather than competing, and potentially posing a major problem for Amazon. Google in turn takes a percentage of each transaction, and charges a flat $4.99 for each order completed.

This poses a huge threat to Amazon. Amazon's biggest advantages over brick-and-mortar were its ability to offer huge lists of products all from the comfort of a user's home at low prices. But now, with Google Shopping Express, users may well be able to get that same huge list available from the home, but with the added advantage of immediacy. Naturally, this isn't going to be much competition in areas that don't have a lot of brick-and-mortar stores; those for whom major stores are available at the end of an hour's drive may never see this service. But if Amazon loses the city business, it may well have a bigger problem on its hands in the long term.

Google Shopping Express may well be the ultimate answer to the question of how to shop from home, but only time will tell if it has legs sufficient to take on Amazon itself essentially where it lives.