When I was a kid I never looked forward to the day when we started up the team fundraising drive. We were expected to go out and sell citrus fruit, nuts, wreaths, and a multitude of other items each and every year. Believe me it was complete drudgery and I looked forward to it about as much as getting a tooth pulled.
Our coach would get us all huddled up and hand us the sales packets and say something like "Go out there and sell lots of stuff." Off we would trudge and try to hawk our wares completely unprepared for our foray into sales. If we had been told something about how to sell? It would have been a whole lot easier.
Teach your kids how to sell. Prepare a script for them to learn and rehearse it with them until they are comfortable. It is very hard to sell something with little or no preparation. This will go a very long way toward promoting sales and boosting the confidence of your sales people.
Make sure your players are rewarded for their efforts. This can be as simple as posting a list of sales leaders at every practice. This will promote an atmosphere of competition and is something that they are already accustomed to if they are actively participating in a sport.
Set mini goal points and when one of them is reached surprise the leaders with a fun activity. Perhaps you might contact their parents and organize a father/son, mother/daughter, or any combination day out. Go bowling, get pizza, take in a movie as a group. That would be fun. This reinforces the ethics of working hard to achieve a goal an being rewarded is associated with accomplishment.
Once the final goal is reached you might reward the entire team for their effort. You might take one practice period and let your team have a night of fun. Forget all the drills, forget the calisthenics. Just an evening of fun play the game. You might prefer to have no interruption of practice and call a special practice instead.
Another thing that would be a big hit to your players and parents is a game where everyone gets to play. Pick 2 team captains and let them choose their team members and then play against each other. Perhaps you could set up a real game complete with cheerleaders and allow the public to attend. The whole idea behind it is to reward their accomplishment as a team. Just make it fun.
If you spend a little time developing the sales person in your kids, and rewarding them for their effort you will find that your fundraiser profits will rise along with the sprit and enjoyment of your sales force.