Web advertising is a goldmine, so it’s not surprising that an online retailer like Amazon would want to have a bigger share of the market.

According to The Wall Street Journal, Amazon plans to replace Google-powered ads on its pages with an in-house ad placement platform. Although Amazon already has a business placing ads on third-party sites, its scope is nowhere near that of Google’s.

The Seattle-based retailer hopes the new system could pull some of Google’s $50 million-a-year advertising business and even that of Microsoft Corp’s.

Amazon has told potential ad partners that testing of a new ad placement platform, dubbed Amazon Sponsored Links, may begin later this year. The system could leverage Amazon’s extensive data about millions of web shoppers and their buying behaviour.

Reid Spice, vice president of media at iCrossing digital agency, commented, “Amazon knows a lot about how people are searching on the site and consumer preferences and histories. It can use that to tailor advertising in ways that probably nobody else can.”

Surely, a new place for placing ads would be a welcome idea for marketers looking to expand their advertising reach.

An advertising war brewing

The two companies have been copying and building upon the other’s products and services in a bid to be go-to place for web shoppers.

For instance, Google’s product-listing ads on Amazon have been invading the retailer’s ecommerce business. On the other hand, Amazon launched its own smartphone against Google’s Android and competes with the tech company’s online storage services.

And now the Amazon Sponsored Links, reportedly, will be similar to Google AdWords in that keyword-targeted ads are placed alongside search results.

Google mainly thrives on its ad-support business. In fact, it generated more profit in the first half of 2014 than Amazon has since it was founded 20 years ago, according to researcher S&P Capital Q.

Amazon operates on thin profit margins from buying and selling goods online, and more advertising could change that in a major way.

While Google will likely maintain a stronghold on online advertising, it looks like Amazon has a good shot at taking a bigger slice of the pie.