In 2018, Amazon kept pushing the envelope, and not just in the retail space. It tested the healthcare market, spoke up in the voice-assistant space, solidified its place as a major player in the digital advertising world, and rolled out private labels at a furious pace. Oh, and it appears to be poised to create a major brick-and-mortar footprint in the near future. 

In this "Behind the Numbers" playlist, track eMarketer's coverage of Amazon through the year.