To someone thinking of breeding, that is still a bit new to the genetics, using the term "het" for something will get them asking some questions and be more likely to get you a sale.

Vender A has a lesser for $300
Vender B has a lesser (het. for lucy) for $350

Perspective buyer asks vender B, what does "het for lucy" mean. Vender B explains, if you were to breed lesser to lesser, you have a 1 in 4 chance of producing this snake (show them the lucy you have for sale). Vender B also can explain some of the other cool combo morphs that can be made with the lesser.

Essentially, Vender B's display caused the perspective buyer to engage in conversation. It can be the conversation that sells the snake, not necessarily the snake itself in some situations. Now as long as Vender B isn't telling lies, I have no problems with him engaging in conversation to help sell his snake.

9/10 times the perspective buyer isn't going to buy, but when one does, Vender B has spent a lot of time explaining his snakes, breeding, etc, so warrants a bit more on the sale.