Amazon Web Services AWS still controls the majority of the market, but Microsoft's Azure has been making inroads, including a recent deal to provide cloud services for retail behemoth Walmart Inc. (WMT) .
Walmart's choice of Microsoft over Amazon may seem like a bad example because they are one of Amazon's fiercest competitors, but being the wide disruptor that Amazon is, Walmart's example isn't that unique, according to Arthur Wood analyst Paul Rodriguez.
"Organizations in certain verticals who feel threatened by AWS will turn to Microsoft as their Cloud infrastructure partner. Case in point, Walmart who is turning to Microsoft Azure as their infrastructure partner. Other verticals like healthcare were also brought to our attention, which may avoid AWS as well," Rodriguez wrote.
Earlier this year, KeyBanc reported that Amazon Web Services had 62% of the cloud services market in the fourth quarter, down from the 68% of the market it controlled a year earlier.
Meanwhile, Azure rose to 20% market share from 16% a year ago and Google (GOOGL) held 12% of the market, up from the 10% it had a year prior.
Shares of Amazon were down 0.1% Wednesday afternoon.