Of or pertaining specifically to relationships, a person who proves themselves worthy of making additional effort to maintain the relationship current. This person may be worthy for many reasons: extraordinary looks, sexual prowess, great talent or exceptional social status.
1. A woman who maintains retro looks, can have a firm grasp as a geek, can cook pie and all whilst also being sexy and loving, is clearly "worth the effort".
2. A beautiful, talented and sexy girl who buys you a Mamiya for your birthday is clearly "worth the effort".
3. A beautiful, intoxicating, talented and awarded woman who is ungrateful, passive and demands a huge amount of caring, rather than attention is probably not "worth the effort".