A pizza place introduces loyalty cards for its customers. Every time a customer buys pizza, they get a stamp in their loyalty cards. When the card fills with six stamps, they get a pizza.
Some months later, they run the same campaign again. But there is a small difference. They customers need to collect eight stamps , instead of the six earlier, to get a pizza. But they were given a "head start." When the customers received their cards, there were two stamps already stuck in the card. (So effectively, they need to eat only six pizzas to get a free pizza just like before)
Now the question to you is, which campaign was more successful? I mean, in which campaign did customers eat pizzas regularly and get the loyalty bonus?