The Mountain View, California-based company is No. 1 in the $626.9 billion global digital ad market, according to 2023 estimates by research firm EMarketer, with the US representing the biggest piece. Alphabet’s ad operations are expected to bring in $73.8 billion in US digital ad revenue in 2023. Most of that, $58.50 billion, comes from Google’s search advertising business. The remaining $15.29 billion is from display ads. Google runs an ad-buying service for marketers and an ad-selling one for publishers, as well as a trading exchange where both sides complete transactions in lightning-fast auctions.