Brian O’Kelley built AppNexus Inc to help companies advertise anywhere on the Internet. Its software plugged into virtually every digital ad-trading hub, including those from Google, the biggest ad seller, and Google’s YouTube video service. By 2014, AppNexus was valued at US$1.2bil (RM4.93bil).
Then, in 2015, Google stopped letting companies buy ads on YouTube using outside software. The move got more marketers to use Google ad services. It also created a glaring hole for AppNexus: The startup could no longer give customers access to the largest supply of online video. It never really recovered.