Joel Spolsky's interview in Founders at work mentions that fogcreek spent time on building out an affiliates program that didn't amount to much. 6 to 12 month

Joel Spolsky's interview in Founders at work mentions that fogcreek spent time on building out an affiliates program that didn't amount to much. 6 to 12 months from now I would like to know what % of sales for 37 signals comes from this program, and if it was actually worth their time building it.