"Most popular models" are based on ratings. The more your members rate a model the higher the score is.
If you want to override the ratings then edit each model and choose the "override votes" option. This allows you to set the votes for this model and is mainly used to control which models show on the "most popular models" top list. You must have the member's area secured requiring a username and password. When a user rates a model the rating is saved to that user's profile so they can't repeatedly rate the same model.
