Here are five sales benefits of calling at the top when you prospect:

1. You will have the attention of the ultimate decision maker of the sale
2. You will shorten your sales cycle as a result of being with the decision maker
3. When you run into problems with people that manage or administer your program, service or product you have a relationship with someone that can fix the problem.
4. If the problems you uncover are real problems you will be in front of the person that will find the money to fix the problem and complete the sale
5. When you call at the top you will know if a current relationship will derail you from getting the sale.

Your decision when you are prospecting is to decide:  How important is it for you to have these 5 sales benefits.  If these benefits won't help you sell more business, more quickly at higher margins then keep calling on those that can only tell you know, limit your budget, and limit your abililty to effectively implement a plan, program or service the exceeds the prospects expectations.