Serenity Spa is considering a Groupon Campaign. They typically charge $90 for a one-hour massage with a registered massage therapist (RMT). They decide to offer 100 massages at a 60% discount, and Groupon will take 50% of their revenue from this campaign. If Serenity Spa pays its RMTs $35 per hour, how much will they lose/gain in total for this campaign? If 15% of those who redeem the coupon come back for two more massages at full price, how does it affect the costs/benefits of the campaign, in term of revenue?