This achievement happens if you complete at least one Daily Challenge per day for an entire week.
Once you start the game you'll be presented with your three daily challenges. Challenges range from things like "get all gold moves on X songs", or "dance to X songs in sweat mode", etc. Each one awards an amount of mojo which you can spend in the gift machine.
If you don't have Just Dance unlimited then the 3rd challenge will be to subscribe to JD Unlimited. If you do have JD Unlimited (either because you purchased or are doing the 30 day trial) then the 3rd challenge will always be something related to JD Unlimited songs.
It's maybe worth noting that the "subscribe to JD unlimited" challenge does count towards this achievement.
But simply do (at least) one of these every day for an entire week and the achievement will be yours. I'm not sure what time zone the game uses, so perhaps to be safe, try to play around the same time every day.