You're back at the start again though - if I wasn't going to buy it, then the vendor hasn't lost anything if I steal it. All that happens is I gain a free experience I would otherwise not have had.
If you run a store, and a customer shows interest in a product and physically touches it is he/she stealing if she chooses not to buy it? Let's say it's perfume, and the customer samples some of the perfume, then decides not to buy it. The customer has experienced it; if the customer doesn't buy the perfume, is that stealing?