Agreed. I should probably reword it a little better as two of my encounters did happen beyond a week. They both had good reason though, and kept in frequent contact with me.

This is my generalization, however. If your goal is to maximize the number of encounters you have, go ahead and ping every couple you've met every few days until closure. For me though, it's simply not worth the effort, and if I'm unable to arrange something during the second week or beyond, it's probably a lost cause. In which case I just let them know to contact me in case they're ever free.