The secret of the Roush effect

When Gerald Roush died in late May, he left behind the Ferrari Market Letter. This newsletter, which he started and ran, had nearly 5,000 subscribers, paying him $130 a year for a subscription. Do the math! It's a good living--even without a fancy website.

The newsletter, it appears, was not just lucrative, it was a bargain. It chronicled the pricing, whereabouts and details of just about every Ferrari ever made. If you were a buyer or a seller, you subscribed. If you wanted to run an ad, you ...