My role was nowhere near as high-powered as the other freelancers on here, but 20-odd years ago I had a Betterware round for 18 months. It was commission-only and consumed my every waking hour, but ultimately it was going to pay for my DD's orthodontic treatment.
Most of the people I left catalogues with were perfectly pleasant about returning them even if they weren't interested in ordering anything, but the people at one particular address left me a very unpleasant message. I made a note not to leave any more catalogues at their address (basically what they were asking me to do, once I got past the bit where they called me THICK in capital letters).
...At that time, Betterware was in competition with Kleeneze, and every so often on my rounds I'd find a Kleeneze rep had beaten me to one street and there were unwanted Kleeneze catalogues waiting on the doorsteps for collection just as I was delivering my (equally unwanted) Betterware catalogues. Naturally, I'd check which Kleeneze distributor was working my route. Their order forms carried their name and address - and about a year after the unpleasant message, who did I find trying to build a career as a Kleeneze rep but the woman from the house that had left me the nasty message! One of her catalogues remained uncollected for a fortnight or so, and eventually I lifted it myself and kept it.
A few months later, at the height of the Christmas campaign and with utterly unrealistic targets to make any kind of bonus, I was getting close to burn-out and knew I needed to pack it in for my own sanity. I'd also discovered, in the meantime, that my DD's orthodontic treatment did meet NHS guidelines and would be free after all, so I no longer needed to work like a donkey. And the money I'd raised was enough to cover the (then very modest) OU tuition fees for several years, so I registered to start a degree on my 40th birthday.
"Oh, not to worry," said my area co-ordinator breezily, "I've taken on a new lady for this side of town - her name is [name of that Kleeneze rep]..." and I replied, "...And she lives at [address], right? Did she tell you she used to be a Kleeneze rep?"
...No, not a word about that! So with a grand flourish I handed over the old catalogue and said, "She left me the most unpleasant message I've ever read. If you take her on, I'll quit on the spot."
My poor co-ordinator had no choice in the matter - the other woman had applied via head office, who simply ordered the area co-ordinator to take her on and support her - but when she said as much to me, I just handed back the forthcoming week's boxes of 150 catalogues and said cheerfully, "OK, I quit. You'd better give these to [Kleeneze rep] instead. Cheerio!"
Last laugh was on me - the Kleeneze woman was equally useless at Betterware and only lasted a fortnight. The area co-ordinator had to cover my old territory herself for a couple of months, telling one customer after another, "SomewhereIslands has left to go to university"...only to hear, over and over, "I'm not surprised - she was much too good to do this for the rest of her life!" 
(Moral of this rambling tale: do it! Something better will always come along.)