Anyone who's ever had to put together an office party, a company picnic, a concert, or, really, any other sort of event of any kind whatsoever, has probably had to go and look for a good party tent. The party tents just add a certain level of professionalism and, well, eventfulness, to any event. You can use the tent as a beer tent, a food tent or even a bad trip tent.
If you like to be able to just get a party started no matter where you are, what time of day it is or what the weather, then one of these, plus a case of beer and a boom box, is all you need to keep an instant party tent in your trunk no matter what. At the beach and it starts raining? Prop the tent up and you're good to go.
If you sell anything for a living, if you do the swap meet rounds, if you go to trade shows or otherwise need some sort of outdoor shelter for your booth or space at a convention or sales place, well, just because it's called a party tent doesn't mean it can only be used for parties. It really adds that level of professionalism you're looking for when trying to draw in some customers. The use of party tents for your business can be a key thing.
As for the people who don't need one of these? People who never have, and never will, host an impromptu party, people who don't own their own sales business, and people who don't ever need to arrange or host any sort of public event.