I wonder if it would help to expand your options. Right now you are looking at two options.


1. Stay at a busy store with a coworker who unfairly takes 70% of the sales.
2. Transfer to a quiet store where you have fewer sales.

There are other options. You could take your sales skills and work for another company. You could transfer to a different store and make more money than you think. You could ask management to make sure David does his fair share of the stocking and other work and stops hogging all the customers. Maybe you could make a case that the sales would be even better if other people had an opportunity to meet customers. You could look for a job that has nothing to do with sales. Maybe management at this company, to make sure there aren't more Davids? I'm sure there are even more different options you can think of. Sometimes it is hard to see opportunity because we are so focused on one particular negative.