I agree with many of the above suggestions. I have 5 LQS within a 30 minute drive from me, and I try to hit them all and give them some business.
Sales are a great way to get customers in, great customer service is also vital so they come back, sew-ins and affordable classes get people in your stores too. Each LQS should have a sign-up sheet so first-time customers can sign-up for the shop's newsletter an stay updated and coming back.
One of the shops near here is starting free demos every month, I think it is a cool way to get quilters in to brush up on techniques or learn new ones for free, and I bet many will leave with a little something from the shop.
Also, guest speakers are a huge draw to quilters.
I guess I am trying to say, whatever the shop can do to lure people in, will likely encourage sales, because most of use would likely leave with something.