The engine named Desire
Since the times of Buddha, and perhaps before that too, much has been said and written about desire. From being vilified as the root cause of all evil - Pink Floyd just used the word Money - to being turned into a virtue - Ayn Rand used the word Selfishness - it has never lost its haloed status as one of the core points of human discourse across time-periods and cultures.
Little surprise therefore that there is nothing around us that isn't really driven by desire. In fact the very value that everything around us seems to be working at generating is basically wrt some desire or the other.
And that's where there brands come in. Products performa a function and cater to needs, they enable one to 'do' something. Brands however address desires. And intrinsic to attainment of desires is feelings - rooted in the brain releasing some positive happy hormone every time a desire is met - through dopamine and its cousins.
That's exactly what brands are meant to do - to help the customers attain a desire - to fit in, to stand out, to be in control, to get rid of some guilt and so on. The deeper and higher the desire, the stronger the feelings and in turn the bond between the customer and the brand.
So, to understand what should the brand deliver on, one needs to understand the root desire the customer is looking at fulfilling. Don't be surprised if you discover that all desires finally stem out of six primal needs - the 6 S's - Survival, Safety, Security, Sustenance, Status and Sex. Let's however leave that for another day.