Impulse buying can account for a significant percentage of all supermarket purchases (I've seen different research reports peg it between 20% to 60%. One of the latest reports puts it closer to 20% See article).
Market Basket Analysis enables retailers to discover which items tend to be bought together. Retailers use it to understand the purchase behavior of groups of customers, and use it for cross-selling, store design, discount plans and promotions. A great example of cross selling is Amazon.com's recommendation engine that gives you suggestions of books you may like based on your purchases.
Microsoft SQL Server 2008 empowers informed decisions with predictive analysis through intuitive data mining ─ seamlessly integrated within the Microsoft Business Intelligence platform and extensible into business applications.
SQL Server Analysis Services 2008 has many rich and innovative data mining algorithms, most developed by Microsoft Research to support common business problems promptly and accurately. One of the algorithms enables Market Basket Analysis.
This VIDEO WALKTHROUGH shows how you can use the Shopping Basket Analysis Tool within Excel 2007.
To test this out you will need: