This is a rule I’ve been using for a while now. Great for making web apps “good”, but can be used in other places too (product design, customer service, copywriting, advertising). Being “good” is a route to “win”.
80% practicality (”job done”); 10% glamour; 10% character.
So how does it work?
“Job done” practicality is the price of entry for your app (or product etc). You need to to give the user what they want, helping them achieve their goal easily and with minimal fuss. If you can’t deliver on this, the app or product will probably fail. It won’t be good, it won’t sell, it won’t gain users. You need to at least do what it says on the tin. That can be a lot of work, as rule of thumb, probably 80% of your effort.
Being ruthless about delivering practically is a great tactic for many reasons, including:
- can reduce your overall costs (by removing un-needed stuff that you have to make and support)
- benefits users (by decreasing the friction of using your app or product)
Practicality also has a couple of serious limitations:
- doesn’t distinguish you much from your competitors. Being better at “job done” might keep your existing customers, but it probably won’t create passionate advocacy and recommendation. Passionate advocacy and recommendation is great, it’s a route to “win”.
- practicality alone tends to lack warmth, soul, personality….the stuff that makes us human
Glamour make people feel smart, make things shiny, make people go ‘ooh’.
Emphasising glamour might sound shallow, but – take a peek – we can take glamour to mean beauty, elegance, chic, style; charisma, charm, magnetism, desirability (worth). The word ‘sprezzatura‘ might be better, but I’d be forgetting how to spell it 
In a web app, glamour comes from the appearance of effortlessness. This could be things like outstanding graphic design or providing interactions that feel just great. Using javascript drag-and-drop to make a list much easier to use is glamour. Slideshows and lightboxes can be glamour. One way to increase glamour is by showcasing the user’s stuff and keeping your app out of the way – perfectly crafted background can enhance the glamour of a foreground subject.
Be ruthless with glamour. The goal is to flatter the user, not the designer. Make the user feel smart, make them feel they’ve made great choices. Glamour done wrong = tawdry, cheap, nasty, irritating, and might give you a rash.
Character is who we are. Who we are is a factor in having users come back to us, and in creating passionate advocacy and recommendation. Be ruthless with character – you’ll be judged by it. Be ruthless, but be generous. Character comes out in tone of voice, customer service, and (worthwhile) quirks. I could write more on this, but I couldn’t think of anything useful and I’m running out of time. You probably get it, ‘cos you’re smart people 
– postscript —
This rule *is not* an 80-20 law, although it might look like one » Learn why.
This rule *is* effectively a variation of “Sell the sizzle, not the steak”
