On the earnings call, Huffman said that Google's algorithm changes take place about twice a year, adding "not the first, not the last."
"It primarily affects logged-out users in the U.S.," he said. "This one was particularly interesting because there really was a swing down, but then a recovery shortly thereafter happened right at the end of the quarter."
Despite missing on user number, the company otherwise reported a strong quarter and provided optimistic guidance.