Simply put, a Wanted score is a number that reflects how complete your profile is. Companies value profiles with a lot of information, so the higher your score the more attractive your profile will seem to potential employers.
How is the score calculated?
The score is calculated based on how complete your profile is. You can also improve your score by taking actions on the site, such as increasing your connections.
What is a good score?
If you are around 50 you have the basics complete. If you are around 100 your profile is considered extremely attractive.