Upselling and data harvesting
“This item costs 5.99 £/€/$, but if you buy three there is a 30% discount.” “No, thanks. One is enough.” “Do you have the loyalty card? It's free.” “No, and I am not interested in one.” “But you could have a 15% discount!” “No, thanks.” “Would you like the receipt to be emailed to you?” “No, thanks.” “But you could get discounts for future purchases!” “No, thanks. Goodbye.”
Every. Damn. Time.