You can’t sell junk, unless you like junk, in which case it is not junk. The point is: You must believe in what you sell. I have a saying I have used several times, about several different products, and it has been true (or at least I believed it was at the time): “Our product is the best at what it does”.
I want to understand the technology behind our products, this way I can communicate with IT departments and the most advanced users; I want to understand our invoicing so that I can communicate with accounting; I want to be trained on our products so that I can communicate to department heads how easy the transition will be; and I want to use our product so that I can communicate to users not just features, but actual scenarios, workflows, and benefits (big difference between features and benefits, people actually care about benefits). I know that is quite a bit of desire to communicate effectively, but that is what is neede
So, when you decide to sell something make sure it is a product you are willing to back and build a reputation on, it is easy for an interested party to see if you personally believe in what you are saying and selling.