My guess is you're seeing the L2 chargers outside a grocery store or some such. Those charge so slowly you aren't expected to stick around and look at them, you plug in and do your grocery shopping. If you're looking to charge a significant amount, these are not it.

I've never seen a Level 3 charger with an advertisement. Hell, 90% of the time I have to scour the parking lot to find the charger because they're usually hidden and unlabeled.

Bonus points, if you're fortunate enough to have access to a power outlet where you park, you can usually do 99% of your charging from home, ad free.