Ask HN: Why are people asking to buy my chrome extension?

Hi, Last year, I made a chrome extension that took about a month to code, that helps you annotate screenshots. Every now and then, someone writes to me, or contacts me through the google store, to ask me if I am interested in selling the extension to them. This is weird to me because the project doesn't generate any money, is not particularly hard to copy, and has a ton of competitors. The fact that I get contacted fairly frequently is suspicious to me. Are these scam attempts? Like: they would ask me to acquire the software, and then ask for $x upfront to write up the paperwork? Has this happened to other people before?