If weak ties do favors for us, they start to like us. Then they become even more likely to grant us additional favors in the future. Franklin decided that if he wanted to get someone on his side, he ought to ask for a favor.
When you do someone a favour and they obviously 'owe you one,' wait a few weeks. Don't make it look like tit for tat. Allow the favour asker the pleasurable myth that you joyfully did the favour with no thought of what you're going to get in return.
Technique 82: Tit for (wait ... wait) tat When people do you favours and it's obvious 'they owe you one,' wait a suitable amount of time before asking them to 'pay.' Let them enjoy the fact (or fiction) that you did it out of friendship. Don't call in your tit for their tat too swiftly.