One perfectly valid and useful business case for Tor is accessing a competitor's website to check prices.
While it is unlikely, it is possible a competitor might recognize your IP as coming from your business and possibly send you a page that is not the same page directed towards the rest of the public.
At the very least it would know you accessed its site and if you do so on a schedule, it might change its pricing strategy accordingly. For example if you are always checking prices on a Tuesday it might roll out price changes on Wednesday, rendering your information useless.
8If it's illeegal information, you REALLY don't want anybody to see it! – Daniel H – 2009-08-18T02:15:01.017