When I asked him how knowledgable the salesman was about the industry, he admitted that the salesman had very little knowledge of the ins and outs of the product. My response to him was this -
He can't think outside the box if he's never been inside it.
Think about it. It's hard to find creative answers when you don't have the knowledge base to begin with.
The lesson? Make sure you take the time to teach your salespeople as much as you can about the products/services you offer. Tell them how you work with a prospect - even show them. Take them with you on a sales call. Then walk them through your process. Set them up for success - theirs and yours.