Growth in the $270 billion cloud infrastructure market, a cash engine for Amazon.com, microsft and Alphabet, gives the clearest sign yet that AI investment is bearing fruit after investors drove those stocks to record highs, thanks to optimism about the emerging technology.“Looking across AWS, Microsoft Azure and Google Cloud, it is clear that two things are happening simultaneously – AI is contributing to growth, but also the rest of cloud spending is accelerating,” said D.A. Davidson & Co analyst Gil Luria.“The number of Azure AI customers continues to grow and average spend continues to increase,” Microsoft CEO Satya Nadella said on the company earnings call, adding that more than 65% of the Fortune 500 companies were Azure OpenAI Service customers.