Several years ago there was a show, it might have been 20/20 or something similiar, the readers they interviewed admitted that they never read cards in their lives, THEY ALL worked from a guide sheet (sent in the mail in a packet) explaining the meanings of the cards, just like a lwb, the main thing was to keep the sitter on the line for a certian period of time, I think it was a minimum of 15 minutes, and it didn't really matter what they said as long as it sounded good, they all worked from their homes, they had a special phone line set up for work and you never could get the same person again if you wanted to, it was all random. You as the reader would never know if the reading was helpful or not. The worst is they were only getting a very small portion of the money taken in.
There's nothing wrong with doing readings over the phone, I've done tons, but I'll be damned if someone else is going to profit off my readings other than me
I'm sure not all are like that, I guess it wouldn't hurt to check into them, get all the facts and see if it's something you can benefit from. I suppose we all have to start somewhere but if your looking to build a clientele I think online would be the way to go, that way the sitter can come back and find you for another reading, then word of mouth gets around and you can start building.
Good luck to you!