Man of Internet Wisdom! :) Surely you jest! ;)
A few things which ring true in my experience:
1. If you're selling something that is desperately hard to explain you'd better be selling it to the right people.
2. If you understand exactly what you're selling and expect your customers to understand also; you've got your blinkers on.
3. The jaron should come seperately from the sale. So if you need to explain something with heavy jargon make two paths to the sale. One which says "read more about widget products" and links through to sales page and one which goes straight to the sales page for the folks who already know about widget products. People like to figure things out for themselves and feel clever. Make all the information easily available.
4. Use FAQ's and sprinkle links for tutorials, "more about widgets" and "what is widget anyhow?" pages liberally.When you're trying to reduce the number of clicks to your "money page" this can help to keep the number of clicks low.
5. The bottom line is that you need to make sure that a complete simpleton who's a complete stranger to your product can find all the information they need to make an informed choice and that your regular customer doesn't feel that her intelligence is being insulted. Easier said than done.
6. Nobody has time to learn complicated things which they don't need to know, especially on the internet.
7. Keep people entertained, make them laugh or snicker once in a while. As long as people are getting some sort of buzz out of your wriing they'll keep reading.