Or you could actively try to hide the fact that your card shop exists. Take for example this street in down town Chippewa Falls, WI. I was there last week visiting family and getting things done for my wedding at the end of May. Somewhere on this street is a card shop but you wouldn't know unless you tracked it down on Topps.com.
So where's the card shop? We've got a lot going on here...apartments, a law firm, a Christian Coffeshop [whatever that means exactly], a news paper machine, even an open door, but don't be fooled by that.
Behind that unmarked door, with no signage other than a door sign marking that they are open from 11am-4pm Tuesday-Saturday is a shop called Sportscards Plus. Sportscards "plus" what exactly? I have no idea.
This is the only card shop within 50 miles of my home town of Eau Claire. I swear to you the only way you would ever possibly know that sports cards are for sale there is if you happened to walk up to the window put your hands up to your eyes to block the glare and peer inside.
For the love of baseball cards, please get at least one sign!