Lots of tiny psychological effects

After all there seems to be a sound theory why we  fall for the warm and fuzzy ad servings.  Sendhil Mullainathan, a Harvard economist, has found a connection between market demand and our psychological  map.

tiny psychological effects can have potentially enormous impact on demand, more of an impact than price

This theory comes out more convincing when taken in the context of recent software success stories . Take all the recent blockbusters - Flickr, MovableType, iPOD, iTunes, Google Map, and Skype. They all have a brilliant execution on the psychological side and have done excellent job getting their user's initial acceptance purely at the design level.

Lesson from the economics is that you should  make your product design keeping  user's emotional need as well as his functional needs.

Net Take-way - work on lot of tiny psychological effects for your product.