Google's cloud chief Thomas Kurian said the company's existing customers are shelling out "roughly 50% more" than they've already committed to spend on its products, which helped drive its red-hot cloud growth during the second quarter.

"Our existing customers have increased their spend when they make a commitment to us," Kurian told CNBC's Jim Cramer on Thursday. "They're spending roughly 50% more than the commitment, and so it comes down to the differentiation in our product portfolio, the strength we have in our go-to-market execution, and you see that in both top line and operating income growth."

This is breaking news. Please refresh for updates.