The city cafe 7-11 is having a promotion of 30% off the second cup in Taiwan from now till February 21st.
Just tried this out for the first time called "owing a cup." (欠杯） Essentially, since I can not gonna drink both cups today, I can go back to pick it up tomorrow with the receipt (or within the promotional period).
Starbucks coffee is having a buy-one-get-one-free offer today up till 8:00 PM, on February 4th 2012, in Taiwan because people have to work today to make up for the extra vacation day during the Chinese New Year break.
A long long line and a long wait thereafter though.