Would you rather strike an Internet partnership with Yahoo! or with Marriott? Emerick Woods, 44, CEO of Vicinity Corp., has been involved in deals with both companies -- and only one of them worked out well.

Guess what? It wasn't the Yahoo! deal, even though that alliance did provide a way for Vicinity to share Yahoo!'s online Yellow Pages listings and mapping services with millions of Internet users. Instead, Palo Alto-based Vicinity has discovered that a deal with the much less flashy Marriott is profitable, easy to manage, and a perfect partnership for gaining new business.

Such hit-and-miss experiences aren't anomalies. They are a fact of life in the fast-changing and sometimes-chaotic Internet economy. Nearly every Net company has decided that it can't conquer the world alone. These companies are feverishly signing deals, hoping that the right alliances can help them meet their business goals.

A recent survey conducted by Forrester Research Inc. found that Web media companies have an average of 14 partnerships each and that this number is expected to rise to 69 partnerships within three years. Yet partners say that in 30% to 50% of these cases, they either wouldn't renew the deal on current terms or they weren't sure that the pact was worth renewing.

So what does it take to strike a winning Internet alliance? Many of the answers to this question involve classic business principles that are being rediscovered by Internet executives. First, be sure to manage expectations of the partnership, so that neither side bets on a miracle. Second, don't get stuck in shotgun pairings with companies that have customers or goals that are incompatible with yours. Third, make room for revisions, because it's hard to know how companies' strategies and opportunities will change. And fourth, be sure that there's a personal bond between the companies that will sustain the alliance.

But another lesson is emerging that is very Net specific. As the Internet economy moves away from the idea of growth at all costs, companies are learning about the hazards of cash-for-traffic deals -- in which one partner bets a lot of money on the chance to pitch its wares on the other partner's heavily visited site. In the end, most Internet businesses don't need momentary exposure to a million tire kickers; they need a few thousand regular users who will do a lot of business. That understanding is causing companies to forgo seemingly glamorous deals that buy a lot of traffic for narrower but more-focused deals that can land a few vital customers.

Vicinity's early stumbles -- and its rebound -- embody such old-school business lessons. When Vicinity was founded in 1995, the executives of the e-retail marketing-services company viewed Yahoo! as a prized partner that was worth landing on almost any terms. Vicinity arranged to license Yellow Pages data from an outside vendor, and then to repackage that data and put it on the Yahoo! site. It wasn't clear how this could be done profitably, but Vicinity hoped that payments from Yahoo! would exceed the data costs.

It didn't take long for Vicinity to realize that the Yahoo! deal, for all of its cachet, was a business disaster. Third-party data was not only expensive, but often out-of-date, requiring constant revision. Payments from Yahoo! weren't nearly as generous as Vicinity had hoped. "At one point, we calculated that the Yahoo! partnership was using up 88% of our bandwidth and providing just 9% to 11% of our revenue,'' recalls Tim Bacci, 41, a Vicinity cofounder.