Selling related products
There is a lot that could be done with selling related merchandise. You can explore selling the obvious stuff like T shirts, and mugs. Or, you may want to look at selling hardware. We've had some success selling mini-itx components and small computers here at DSL.
If you want to sell logo clothing and merchandice you may want to outsource the process to a company such as CafePress. The only down side there is that your percentage of sales tend to be low on these items.
Our small computer store brings in a steady stream of sales. By buying directly from the manufacturers or the wholesale distributors in volume, we are able to charge competitive market rates and still retain a small profit. The down side of this approach is that it is labor intensive, and there are often customer service issues which eat into your development time.