The concept

A one-click upsell is a complementary offer shown to the buyer right after the first purchase is approved, charged with a single click because it reuses the card details already entered at checkout, without asking the buyer to type everything again.

By removing the friction of filling in payment details again, the one-click upsell converts better than an offer that requires a separate, full checkout.

How it shows up in practice

You sell an infoproduct course and, right after the person pays, a screen appears offering a complement at an accessible price. The buyer doesn't need to go back to the full checkout, doesn't need to enter the card again, it's just one click. The acceptance rate is high because friction is minimal: the person is already there, already decided to pay, and the second offer feels like a natural add-on.

The simpler it is for the customer to understand the offer and move forward, the shorter the distance between interest and purchase.

Russell Brunson Source: concept developed in DotCom Secrets. Paraphrased by the editorial team.

This quick one-click flow generates more revenue per customer without increasing operational costs. An offer that required going back to the full checkout would have much lower conversion, because there the buyer stops and thinks twice and often gives up.