What does the letters OTO mean in internet marketing?

OTO generally stands for one time offer. You usually see this as an upsell strategy to an offer. Here's what usually happens during the process, you buy a product or service for a low entry price like $29 or $39, somewhere in that area. Once you get "in the door" you are offered a OTO. Marketers call it this so you get the feeling that you need to buy, after you decline it won't be offered again. It's a marketing ploy that works well. Is it alway a good idea to jump into these OTO's, that depends on you.