A story needs to be valuable. We don't care about value to just anybody; it needs to be valuable to the customer. Developers may have (legitimate) concerns, but these framed in a way that makes the customer perceive them as important.
This is especially an issue when splitting stories. Think of a whole story as a multi-layer cake, e.g., a network layer, a persistence layer, a logic layer, and a presentation layer. When we split a story, we're serving up only part of that cake. We want to give the customer the essence of the whole cake, and the best way is to slice vertically through the layers. Developers often have an inclination to work on only one layer at a time (and get it "right"); but a full database layer (for example) has little value to the customer if there's no presentation layer.
Riffing on Wake’s cake metaphor, I wondered if people who are working in layers could be playfully coaxed to those tasty vertical slices through a theme song. Perhaps we play the song at sprint demos. You know, to fill up the space where the team normal shows working software.
Try eating only the frosting on a cake and see how quickly you develop a sweetly sick feeling. So I felt that the sweetly sick song MacArthur Park would be apropos for all layer lovers.
Listen to these lyrics:
MacArthur's Park is melting in the dark
All the sweet, green icing flowing down
Someone left the cake out in the rain
I don't think that I can take it
'Cause it took so long to bake it
And I’ll never have that recipe again, oh no
This is a 60s song so let me translate the lyrics to Agile:
The customer’s love for your product is melting
During integration your sweet, sweet tests flow from green to red
When a market storm rolls up on us, we couldn’t deliver the cake fast enough
The cake’s features are no longer valuable to our customers, and we don’t think we can take it
Takes a long time to bake a whole new cake
We missed a major market opportunity, and we’ll never have that chance again, oh no
PS. Note to self. Never again read Mike Cohn's book User Stories Applied while watching American Idol.