While a few decades ago, retail banks primarily made profits by leveraging their treasury office, recent years have seen fee income become a major source of profitability. Accepting deposits from customers and lending to other customers is one of the core functions of the treasury. However, charging for current or savings accounts with add-on facilities such as breakdown cover, mobile and other insurances, and so on, has become a lucrative avenue for banks. One retail bank has a plain vanilla classic bank account, mid-tier premier, and a top-of-the-range, benefits included platinum account. The classic account is offered free and the premier and platinum have fees of $10 and $20 per month respectively. The marketing team has just relaunched the fee-based accounts with added benefits. The finance team wanted a projection of how much revenue could be generated via the premier and the platinum accounts.