never made its mark as a result of those changes and eventually sold itself to at&t i'm join bid brian o'kellyfounder and former ceo of app nexis. brian, before we get into your story, julia, remind us what the market share is these days when we're talking about the online advertising market. >> there's no question, kelly, that google and facebook together dominate digital advertising. 60% of the u.s. market share google has 37% of ad marketshare. youtube is estimated to be about 4% these numbers are according to emarketer. what's really notable here is that that market share has been holding steady and we've seen amazon actually make gains now with nearly 9% of digital ad market share but there's no question when it comes to the biggest players in the business, number one is google, number two is facebook and their reach in scope, especially when it comes to mobile advertising, which is where the growth market is right now, is pretty massive. >> brian, i remember app nexus there were many of these at the time you were basically the marketplace where people could come and you would place them