Amazon is quietly building a new team to develop its own supply-side platform (SSP) for its own properties. This move is a sign of Amazon's growing ambition in the advertising space, and it could pose a threat to Google's dominance in the market. An SSP is a software platform that allows publishers to sell their ad inventory to advertisers. Amazon currently uses a third-party SSP for its own properties, but the company is now building its own in-house solution. This will give Amazon more control over how its ad inventory is sold, and it could help the company to generate more revenue from advertising.