It's nice to store any information that's nice to have, but not important enough to expressly record somewhere. "search, don't sort" applies especially well to

It's nice to store any information that's nice to have, but not important enough to expressly record somewhere. "search, don't sort" applies especially well to this kind of info. Addresses were already mentioned, but that also applies to IBAN, email addresses, door codes, restaurants... It's also some kind of light diary: you can easily deduce what you were doing on a certain day if you look at the corresponding message. For me it's not important enough that I would want to migrate it to another app if I were switching (I'd just save the DB), but it's not completely useless either. And of course some people just store everything there, including things that were not messages in the first, just like they do with email. You can argue that they shouldn't, but if that's what they want... Obviously that's also a privacy risk, e.g. in case you lose your phone. There are many countries where I wouldn't keep my chat history for more than one week.