I would somehow show or tell of all the greats who do play with washburn guitars, like make a list. Also maybe tell how long they have been around, what "tried and true" methofds are used to make their guitars (sorta like if it works don't fix it...).
When I think of marketing in general, getting something associated with a big name gets it recongnized, sure, but since when is george formeman associated with cooking untill his grill came out? It is more overly convincing to me to see someone who actually uses the product and perhaps their career is very closely related to the product that they "promote." I also heavily "buy" into products sold to me by word of mouth, that is, my friends family tell bout something they have been using and have found to work for them. Someone ultimately has to buy and use it first, and if it is a good experience, they will tell and convince their friends/family of it too. I believe the word of mouth is stronger than any comercial I've seen, unless a comercial compels me to spread the word about a possible great product to other friends.