The Bundle Psychology
In Print on Demand, selling one item is hard. Selling two is barely any harder, but twice as profitable. Why? Shipping Arbitrage.
The Shipping Gap
Most providers charge ~$4.50 to ship the first shirt, but only ~$1.50 for the second. That's a $3.00 margin gain on the second unit instantly. You can keep it, or give it back to the customer as a discount to incentivize the sale.
Boost AOV, Lower CPA
If your Facebook Ad costs $15 to get a customer, and they only buy one $25 shirt, you lose money. If a bundle offer convinces them to spend $50, that same $15 ad cost is now 30% of revenue instead of 60%.
Offer: Buy 2, Get 15% Off.
Single Shirt: $25 Price - $18 Cost = $7 Profit.
Two Shirts (No Discount): $50 Price - $33 Cost ($15+$18) = $17 Profit.
Two Shirts (15% Off): $42.50 Price - $33 Cost = $9.50
Profit.
Result: You made $2.50 MORE profit than selling a single shirt, even after giving a
discount. And you likely converted a customer who was on the fence.
Discount FAQ
Yes, use Etsy's "Sales and Coupons" feature to set up a "Minimum Quantity Discount." Set it to 2 or 3 items to auto-apply the discount in the cart.
Absolutely. A "Beach Day Bundle" (Tote Bag + Tank Top) often works better than just "Buy 2 Shirts" because it sells a lifestyle, not just a commodity.