Verizon Communications has made clear what it hopes to gain with the $4.4 billion purchase of AOL: a better way to sell mobile video ads. AOL, ridiculed for its continuing dial-up Internet business, has in the last few years assembled a set of cutting-edge online video technology tools to buy and sell ads automatically in real-time, measure audience metrics and specifically target users based on their preferences. Verizon, meanwhile, has more than 100 million wireless customers and plans to launch a mobile video service that could be ad-supported.