as much as

We tend to consider ourselves as rational decision makers, logically evaluating the costs and benefits of each alternative we encounter. However, we are much more primitive than most assume. A team of economists looked at how consumers reacted to various pitches by banks to take out a loan. A purely rational view would have predicted that interest rates would be the only factor that had an impact. But the scientists varied more than just the interest rate; they also tested how persuasive other approaches might be. For instance, some letters offered a chance to win a cell phone in a lottery if the customer came in to inquire about a loan. They found that such an offer increased loan inquiries by as much as dropping the interest rate five points. For a $50,000 loan, this meant some customers were in essence willing to pay $16,000 more in interest to receive a $100 cell phone.

What does 'as much as' here mean?