The paying to encourage them to stick around is intuitive, but lots of people take the approach of "I want to hire someone ambitious who wants to progress, and

The paying to encourage them to stick around is intuitive, but lots of people take the approach of "I want to hire someone ambitious who wants to progress, and who is willing to work extra hours where required to get the job done because they have a personal drive/desire to succeed" The advice here is effectively "find someone who doesn't have strong career aspirations and ensure they aren't working outside of working hours".