Gartner survey of public cloud services in 2020: AWS had $26.2B in revenue, up ~29% and a 41% share overall, followed by Azure with $12.7B in revenue, up ~60%
Context & Ripple Effects
Gartner's 2020 tally extends a slide that was already visible in the 2018 State of the Cloud report, when AWS's enterprise adoption growth trailed Azure's and analysts flagged a narrowing lead. Even in a year when pandemic-era spending pushed cloud infrastructure demand up 37% YoY, the leader's share kept eroding.
The numbers put the duopoly dynamic on paper: AWS took $26.2B (41% share) growing ~29%, while Azure reached $12.7B growing ~60% — fast enough that the gap in relative terms keeps closing. The trajectory held through later readings, with Canalys showing AWS at 32% and Azure at 19% of Q1 2021 infrastructure spend, before Altimeter's 2024 estimate put them at 31% vs 25%.
First-order effects
- AWS remains the clear public cloud services leader with $26.2B and a 41% share, but it grew ~29% while the overall market outpaced it — meaning its dominance is diluting even as its absolute revenue climbs.
- Microsoft's Azure hit $12.7B at roughly 60% growth, doubling down its rate of expansion versus AWS and cutting AWS's relative lead from roughly 3x revenue in earlier years toward 2x.
Second-order effects
- Competitors below the top two face a squeeze: with AWS and Azure absorbing most incremental enterprise workloads, smaller providers must differentiate on price or vertical specialization rather than breadth.
- Enterprises gain leverage in negotiations as a credible second source reaches scale, pushing AWS to compete harder on discounts and committed-spend terms rather than relying on incumbency.
Third-order effects
- If the pattern holds — leader share drifting from 41% toward low-30s across successive surveys — public cloud consolidates into a durable AWS-Microsoft duopoly with everyone else fighting for single-digit shares, shifting industry power toward whoever can fund the largest capex programs.
The trend: Public cloud is settling into a two-player structure where AWS's absolute scale grows every year but its market share steadily erodes to Azure's faster compounding.