Inuvi is a mobile advertising network for enterprise SMS (also known as A2P or "application-to-person" SMS). We supply short, targeted text ads that a company can insert in the left-over space at the end of notifications and content. Since most notifications are much shorter than 160 characters, sending is free, and since the sender already has a relationship with the recipient, it's not spam. Companies get revenue for their notifications while advertisers get a targeted SMS ad delivered nonintrusively.
A key feature is that publishers can supply whatever targetable information they have to advertisers. Example: we work with a travel service that sends ticketing and flight change SMS notifications to their customers. An international hotel group advertises through these SMSs with ads such as "Save 30% when booking early with us in [city name]", targeting their ads by the destination and arrival date that is included by the travel service in their ad requests.