The Problem

A supermarket has created a new subscription delivery mobile app and wants users to sign up.

Constraints

The following questions and points were crucial to providing a good experience:

-Who is the user, and what are they in the middle of doing when this pop up appears? 

-How relevant the interstitial message is to both of the above will determine how hard you're going to have to work.

-Relevance- they want to see what’s cheaper, but still good. 

-The headline should capture as much of the product as possible, but it's also gotta be short and sweet so as not to discourage the user.

-The body copy should emphasize the secondary value propositions of the product—whatever they are.

-Convenience? Variety? Quality? Rarity? I focussed on the unique value propositions relating to the product that are easily understood at a glance. It also didn't hurt to inject a bit of loss aversion into a modal experience.