As ridesharing apps like Uber and Lyft gain national traction, many have speculated about how brands will tap into the transportation companies' advertising potential. Already, marketers like Starwood Hotels and Chobani have run experiential promos with the mobile players, but James Bellefeuille thinks he has found a more effective business model.

Bellefeuille's startup, Viewswagen, is gearing up for a national launch on May 1, when it will begin reaching out to Lyft, Uber and Sidecar drivers to install tablets in their cars. (Sidecar isn't as popular as the other two, but Viewswagen wants as wide a reach as possible.) Similar to the screens built into taxis in cities like New York and Chicago, the tablets display a set of ads that viewers watch and tap with their fingers.

"Advertising in Ubers and Lyfts are a natural extension [of out-of-home advertising] because this is something that has been happening in taxis across the country for decades," said Bellefeuille.

Ridesharing drivers don't belong to a central organization like a union—they are independent contractors—so Viewswagen needs to work with individual drivers to put its advertising plans into place.

To entice drivers to install the touchscreens, Viewswagen will pay drivers $3 an hour on top of what they make from Uber, Lyft or Sidecar. Bellefeuille believes this revenue boost is significant based on drivers' well-documented wage war.

"If we can give them something that will allow [drivers] to make a little more money, it's likely something they'll participate in as an individual," he said.

Bellefeuille equated his startup's pitch to the relationship that Google AdWords has with publishers in which individual publishers set up their own targeted online campaigns.

After a driver installs a screen, Viewswagen is responsible for managing the display ads that run on the tablets. The goal is to create a demand-side platform that media buyers can then use to schedule campaigns and upload creative.

Targeted transportation ads

Viewswagen is predicated on the idea that typical out-of-home ads aren't as targeted as they could be. Indeed, ridesharing services do fork over a lot of data that marketers could use to zero in on specific demographics or locations.

For example, someone taking a ride to a mall in November may be interested in a holiday deal. Or someone traveling to a mortgage company could see an ad for a local broker.

Viewswagen is testing 25 screens and drivers in its hometown of Minneapolis, with the goal of launching nationwide by the end of the month. Bellefeuille declined to name marketers that want to buy promos, but the ad network could be particularly appealing for local mom-and-pop shops and small businesses.

"That ability to engage one-on-one with customers in physical space has added an incredibly exciting new dimension to OOH," said Damian Gutierrez, associate partner at Control Group.

Sean Cullen, evp of Fluent, added that Uber or Lyft riders' intent gives marketers a deeper look into changing creative on the fly.

"Having a captive, confined audience really also opens up a lot of possibilities for in-car video," he said. "It's possible to evolve the idea of video advertising beyond what's available today in the back of NYC taxis by using location and user data."

Uber, Lyft and Sidecar did not respond to emails requesting a comment. How they handle drivers who go for Viewswagen's pitch will be interesting to monitor down the road.

One can easily imagine the services telling their drivers that the screens are unacceptable. At the same time, the growth of Uber, Lyft and Sidecars is dependent on having a willing army of stoplight Jedis. So if Viewswagen takes off, they'll have to approach the situation delicately.