I'm not sure if this applies, but I've been following a company called Volta Charging which is using an ad based model to compensate for the cost of installing and operating L2 charging stations at public locations.
So far they only operate in So. California, Arizona and Hawaii, but seem to be expanding.
The model is simple. Advertisers pay to sponsor charging stations in public locations, typically high traffic areas like shopping centers, and the EV driver just drives up and plugs in and that is that. I think it is a great idea. Is it sustainable, well I don't have a clue. However, marketing dollars are much less concentrated in broadcast media these days, mostly because broadcast media doesn't have the market penetration it once had, so companies are looking for other avenues to try to promote themselves. Sponsoring charging stations is one way of reaching out to a broader base of potential customers and can give companies "green" credibility through offering free vehicle charging.
If you have a cost sensitive retail location, hotel or multi-use facility, (and who isn't cost sensitive) this is a good way to go with no out-of-pocket expense or administration for the hosting location. If Volta was operating in my locality, I'd be working with my company to install a couple of their stations on our property.
Great to know about Voltacharging, thanks for posting. Their model is a fine example of Permission Marketing. In fact, they're an example of the principles outlined in Seth Godin's book Tribes. It's from a few years back, and still totally relevant. I actually went to the book launch. This whole EV movement is a "tribe" in action-- a group of people with common goals & interests & a leader or leaders who connect & inspire.
I think what's needed is for the auto manufacturers and EV charging network companies to get some leaders out there, spreading the ideas of this great technology. Imagine if we had a Steve Jobs or Sir Richard Branson type stirring up interest, through the marketplace itself. I guess Elon Musk counts, but his influence is limited to his brand in many ways.