The way Ad companies are getting around the whole autoplay video on mobile, is by converting the video to an image sequence and when you touch it, it gets replaced with the actual video. (I know Sizmek does it that way)
The good news (or not) though is that Android and IOS will start letting video autoplay pretty soon. why you ask? well, everyone knows that the autoplay video ban was imposed to save battery life and processing power, but it turns out that playing an image sequence does more "damage" than actually letting the video play.