Fiona and I have been trying to do a bit of a clearout, and as part of that we decided to see if we could get rid of some old academic textbooks, which have been sitting on our shelves pointlessly for a few months (or in my case, a year). As students are only just going back to University, now seemed to be like as good a time as any to flog them.
Initially, I was thinking eBay, but my track record of sellings books on eBay hasn't been great, and I'm not sure that eBay is the first place that people turn to to try and find obscure academic books. Instead, I listed about a dozen of them on Amazon Marketplace. This seems like a good deal, as there's no listing fee, they get listed for 90 days, and the option to buy second-hand versions appears prominantly on all the main Amazon books pages. Unlike eBay, it's not an auction format, but you set a fixed price. Listing is really easy, you just type in the ISBNs, and then it picks out the book straight away. So there's no need to upload photos, type in titles or anything - which just goes to show how useful having unique identifiers can be.
One consequence of the fixed-price selling format, is that, as there seems to be at least ten new or used books already listed for most books, you're always tempted to undercut everyone else by fifty pence or so, in order to try and make the first sale. So the economics seems to be that the more sellers there are, the cheaper the lowest price on offer is, which I guess is fairly obvious.
Anyway, the point of all this is that I was surprised this afternoon to find that three of the books had sold already! That was far faster than I had imagined. If this continues, maybe I'll start adding a few more books.
On the off-chance that you're interested in linguistics or some particular bits of history, have a look at my books for sale.