On the travel club FAQ page, it says:

"How much does it cost to join?
Annual membership is available for only $25.00 (subject to change). With the $5 you get back every time you purchase a ticket at continental.com, you can earn that money back in just two trips."

$10 was the old fee, I believe. When you guys increased the fee to $25, you didn't adjust the following math appropriately.