Moves that allowed major e-commerce players to jockey for position both off and on the Internet made headlines in 2017. "The year was a triumph for market leaders," said Mike Comstock, a senior adviser at GrandCanals. "Leading companies like Amazon, Target and Walmart just got stronger, as they have the resources to either build or buy whatever they need to win." Walmart had been out of the e-commerce race for a long time, but that changed with the $3.3 billion acquisition of Jet in 2016, which led to more acquisitions.