Some sales programs will work on particular customer skills for retail type outlets or stores. Other sales program may focus on e-commerce and internet sales, presenting and selling products wholesale or even international sales strategies and techniques. Very few training providers can offer all types of sales training and using more than one training group is often essential.
Sales training needs to be done by people that have actually experienced the profession, both the daily reality and the challenges as well as the benefits. Avoid trainers that have a great education but little life experience in the field as they often don't understand the reality of working in sales.