I'd be happy with small print that says you have to buy two parking tickets. Nice and small at the bottom so they don't realise and just get slapped with a £90 fine whenever they park like it.
I went to work one day at Disneyland. And a truck took 4 parking spots, right at the front. The lot was packed, people were parking at the end of the rows not even in spots. I drive a very small car. My hood fit under their bumper so I parked in front of them in just one of the spots they took.
I came back to a nasty note on how they paid for 2 spots (but took 4) and how much of an asshole I was for parking in the only spot I could.
in parking lots, the parking is free, unless you're in a parking garage or on a street meter, and even sometimes parking garages don't charge admission. Though it's less common.
These lots are almost always at a store, where people buy things, and the companies make money.