That's such a broad question, it's just impossible to give an accurate answer unfortunately. The theory is that everything is possible to sell or at least "just about" everything. So I think it's plenty safe to assume that people buy board games, DVD sand so on ..., but the issue of making margin comes down to a few basic factors.
Are you selling in a target rich environment?
How strong is your competition?
Are you selling at a competitive price?
Are you providing a competitive service?
Can the products be sourced at the right price?
They're the basic factors, but then on top of those you have things like marketing issues you also need to tick off.
All pretty basic business principals with e-commerce and getting the answer to each of those with give you the ability to assess the viability of a product. It's easy for someone to say "hell yeah, I make a fortune from doing it" and for someone else to say "no chance at all, don't even try" because everyone can have a different answer depending on how many basic factors have been ticked off before trying and even then, without knowing their exact business model you may not be able to replicate their same results.