[bdickason]

Precisely. A good example of this is vintage furniture sellers and refurbishes. They don't really fit well on eBay because of high shipping costs and difficulty to identify pieces and Craigslist is very hard to crack due to regionalization. For example, Hudson, NY has tons of stuff on Craigslist but New York, NY is hugely lacking in antique furniture.

Anyone that is caught in limbo between eBay and Craigslist and thus resorts to flea markets or other 'in-person' gatherings for sales are good targets.