Winning in business is about selling the best product at the best price. If only.

In many industries the difference among competing players is not very large. Often the best way to get an edge, if you can, is getting a gander at what the other guy is going to do before he does it. “Learning everything you can about your competition is time-consuming, but the return on investment is enormous,” says Sally Wright, president of Alliance Consulting Group in New Brunswick, N.J.

But how to spy on your rival without breaking any laws and without spending a ton of money?

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