I just finished a favor and than checked to see if I could do another one but noone wanted it, so I did a random case than re checked for favors, still noone wanted any. Is it 1 per day? or 1 every 4 cases?
If you succesfully solved 4 correct cases (cases+favor), you get a favor. It depends if you are subbed or not in this case, if you get one per day or not.