According to game theory: Do not exploit every advantage just because it exists. In repeated games, you expect to deal with someone on a consistent basis. As such, practice cooperation, leave them with dignity and profit, maximising the incentives for future cooperation. Maximise the relationship that generates transactions, rather than exploiting particular transaction.

If you want someone to help you, stop asking from your need and start from their self-interest. Before you make the request, ask yourself: what do they gain by saying yes, what do they lose by saying no, and How would they feel about themselves by helping you?