Here’s a way to make people buy more of your stuff – give them fewer options. Douglas Coupland called the bewilderment induced by there being too many choices ‘option paralysis’ (‘Generation X’, 1991). Now social psychologists have caught on (‘When choice is demotivating’, 2000, [1]). Offer shoppers a choice of 24 jams and they are less likely to buy a jar than if offered a choice of 6 jams. Offer students a choice of 6 essays, rather than 30 essays, for extra-credit and more will take up the opportunity if there is less choice of essay titles – and, what is more, they write better essays. Students given a similar choice of free chocolates (a restricted choice compared to an extensive choice) made quicker choices (not too suprising) and were happier with the choices they did make once they had made them.
ref
[1] Iyengar, S. S., & Lepper, M. R. 2000. <a href="http://www.columbia.edu/~ss957/whenchoice.html
“>When choice is demotivating: Can one desire too much of a good thing? Journal of Personality and Social Psychology, 79, 995-1006.
Mind Hacks 
That’s something we definitely noticed when planning our wedding. At the beginning I was hunting down loads of options before making a choice. After finding the decisions difficult I switched to looking for three suppliers & choosing from them. I only looked for more if I wasn’t happy with any of the three.
Aha! What you’re doing there is ‘satisficing’ rather than ‘optimising’. Barry Schwartz argues that attempts to optimise (make the best possible choice) often lead to misery – he also claims that having many available options can actually make optimising behaviour *more* likely…