You should explain to them the benefit of making such investment in the first place. That would give them something to think about. Some of the benefits you can highlight are
1. Its helps to achieve EA status which is a requirement for earning income in the TripleClicks Executive Pool.
2. Investment in adverts and co-ops will help to build the affiliates downline which can furnish such affiliates with income for life.
and a host of other benefits.
I hope this helps.
