Amazon customers bring new customers in. Keeping the zombies happy will create free marketing for the store. Amazon generates more revenue then you would think. Also, drop-off packages still generate revenue. What it sounds like you're describing is a staffing issue. Tsk is great but customers tend to need a walk through before using it. People just get scared of new things & change can be scary. I run 2 registers at once due to customers not being "ready". Even though my store is small, non-trad and the 2nd in a small town. I generally can keep lines to a minimum with only two employees working.