After years of unfulfilled promise, local ad networks have reached maturity. Stories of CPMs doubling and large “spot” buys mean that the floodgates have begun opening for networks that offer targeted banners down to local websites. It may mean a bonanza for local media managers, many of whom operate sites with half their inventory unsold. The biggest beneficiaries are likely to be newspaper, TV and yellow pages websites, which control 80% of all local banner advertising, as well as the ad networks themselves.