if you get a website up and offer a free shaker and good prices i'll give you some business. probably not the advice you're looking for but thats all i got =p

but definitely get knowledgeable people in-store (cough cough not gnc) and keep the prices as low as possible. i always think of it as 1% profit with happy buyers will yield better long term gains than 5% profit now and dissatisfied customers.