Generally, companies such as Maybelline require that you have a direct arrangement with them to buy and sell their products. They want to ensure that the distributor--who is trading and making a profit on the Maybelline name--is a responsible person who will handle customer inquiries and complaints in an appropriate fashion (to limit Maybelline's liability).

If you jump into the middle of that arrangement for your own accounts, Maybelline has no way of pre-screening you. It's also likely that if Maybelline got wind of what you were trying to do, it could bring a lawsuit against you to disgorge your profits.

In addition, some companies that work on a wholesale distribution model (and not just a network marketing model) provide their distributors with an exclusive territory. If you were to buy the products from your next-door neighbor and sell to your own accounts, you could well be undercutting his/her rights to sell exclusively in the territory . . . which will not make for a happy and harmonious neighborhood.