Also cars and other merchandise.

Will a giant company come after me for a single rental or two that was decorated with merchandise based on a movie, probably not.

Also, you don't want uncovered windows that either look vacant or a person walking by can look in and check out the merchandise to steal.

I've registered for conferences, bought merchandise, and even had a salaried position where that was the ONLY way of paying/being paid.  

Let's talk about it from the retail merchandise side.

Mostly collecting debts for merchandise sold to stores on credit.

And if salespeople can show us how their services or merchandise will help us solve our problems, they won’t need to sell us.

She'll get discontinued merchandise from the popular furniture chains (American Signature, for example), she'll get some inexpensive stuff from IKEA, she'll buy a lot off of Craigslist for practically nothing, she'll go to estate sales, etc.

https://help.venmo.com/hc/en-us/articles/217532097-Can-I-use-Venmo-to-buy-or-sell-merchandise-goods-or-services-I wouldn't want to take the chance that the other party complains, or that Venmo catches wind of it and pulls money back because of transactions against their terms of service. 

Think inventory like buying and selling cars or merchandise on a web site.