This post is more of general business concept versus specifically designing or optimizing a Yahoo Store.  Regardless, the principle can be easily applied to the Yahoo Store platform.

The Pareto principle, which is also known as the 80/20 rule is an approach that helps you focus on the critical few.  First, a couple of examples to explain what it means.

• Look in your closet, I bet out of the 100 shirts/outfits that you have, you typically wear 20 to 30 of them over and over again.
• How about your eating habits?  Consider the last three months of dinners that you have had.  I bet there are a small subgroup of meals that you have eaten at least once every other week.  Or do you get the same meal every time you go to a fast food restaurant?  Or do you buy something off the menu different everytime?
• Last example… in a 64 pack of Crayons, kids typically only use 10 to 12 colors!  (If you don't believe me, open up the box and count the number of Crayons that are shorter the others.)

The pareto principle basically states that 80% of the impact will come from 20% of the events.  Now the numbers of 80 and 20 are not exact.  Rather, it could be restated as a large proportion of the impact will come from a subgroup of the events.

So how can apply this principle to your Yahoo Store?  Well, how about 80% of your profits are going to come from 20% of your customers?  Or 60% of your traffic is going to come from 15% of keywords.

Take a closer look at your data.  Find the critical few in your day to day work.  Or find the critical few in your store and prioritize your work around these critical few.

It will be time well spent.