For years I have used a service of eBay that allows me to specify search terms for items being sold. I can specify the search terms once, and then eBay sends me an email notice whenever any new item is added to the online auction service with words in the item’s listing that match my search terms. I started doing that perhaps ten years ago or longer, and occasionally it has paid off.
I have often found items for sale that I would not have known about otherwise without manually checking every few days. I have purchased a number of “good finds” over the years, including old family history books, some CD-ROM disks containing genealogy information and county histories, and more. This week, it paid off big time!