In general, people don't migrate between databases. In specific, I find myself migrating from sqlite to either Mysql or Postgres relatively frequently.
That depends on what kind of products you make: If it's a website, then you have absolute control over what stack and database to use. But if you're selling any kind of app that needs a database, then you'll need to support different databases. Some customers won't ask questions and take your default database, others (unfortunately ?) will want it to use their Oracle/SQLServer installation that cost them a bazillion.
