I'm too young to be an affiliate (boo ;_; ), but EdenFantasys sex toy parties are an interesting idea. I've only been to a few sex toy parties, but from those experiences, I've seen the following pros and cons:
Pros: Fun social event, word spreads fast about parties (so a good marketing tool), you get to feel/taste/smell products before you buy, encourages sexual openness.
Cons: Products are oftentimes overpriced. Depending on the company, some parties are women-only, the seller has to buy her own "display/tester set", and needs to have some stock on hand for immediate sales. If customers order something in the catalog that the seller doesn't have on hand, the seller is responsible for placing orders for customers and arranging for pick-up (if customers doesn't want it delivered straight to their doorstep). Again, depending on the company, some sex toy party systems are set up like pyramid schemes. For the sake of selling toys, sometimes sellers will not tell customers about pthalates or whether a toy is porous or non-porous, and just one such careless salesperson could damage the integrity of the program, because bad news travels a lot faster than good news.
My list of cons is a lot longer than the list of pros, but they also aren't disadvantages that are true for every sex toy party program. A lot of it depends on the company's policies and the seller's personal ethics. From what I've seen at sex toy parties and the stuff that's available--printed catalogs, order forms, and company logo bags--there's some extra production cost involved as well. Most of the sex toy programs I've heard of offer incentives for hosting a sex toy party, such as commissions or discounts based on the sales made at a party. Sometimes the company pays for these, other times the seller has to pay for these host benefits.
I can see EF sex toy parties, but it would take a lot of work to set up a good system. I can't be an affiliate for another year or so, but if the sex toy party thing happens... I'd be happy to host one.