Why my own domain?

Well, vanity to some extent, but my original ISP has changed names, via being eaten by ISPs higher up in the food chain, at least six times since I’ve been with them (INST, TECLink, WAS, Meta3, Ayrix, BigNetSouth, …). They have continued to support most of the previous domains, but it’s still annoying. With my own domain, I can have a constant network identity that doesn’t change when I change employer or service provider. Using a spam magnet like hotmail.com for real mail is unacceptible.