Direct sales can be a fantastic business opportunity for a person ready to engage with the public face-to-face. You are literally selling a product directly to the populace, even though the product is made elsewhere and you are acting as a reseller. Therefore a direct sales business needs to have several components in order to make you a comfortable living. Your business plan should clearly state them all. First, the product should obviously be something people want; that should be the heart of your business plan. For example, transistor radios used to be all the rage, but these days, you would have a hard time getting people to buy them (and any market would be spread out too far for you to reach them, even with the internet).
Secondly, you need to ensure that the product you are selling is something you believe in. Most people can tell when you're trying to sell them something you don't believe in. That will also help you determine how much you want to invest in the company, which will be plotted out well in your business plan. You must also be careful how much you budget for expenses, and how often (and to whom) you will sell your products to. That latter will determine how often you'll need to reorder your product, so be sure that your product has an affordable range of price.
Your business plan should also contain a detailed section about your training; you want your investors to understand that you will receive plenty of training from the parent company. Implicit in that section will be the amount of blood, sweat, and tears you will be putting into this project. You will obviously have slow times, and investors will understand that, but you have to have a plan that will show them that you understand you're in for the long haul. Your business plan will be instrumental in serving as the perfect marketing tool for your direct sales business; just bring the right attitude, love for your product, and plan for the future, and you'll be all set.