We've been optimizing press releases for news search engines since March of 2003. Last week, one of my clients, Southwest Airlines, and I co-presented at The Summit for the Future of Measurement, a conference organized by Katie Paine, publisher of The Measurement Standard. Our case study was about using unique tracking links in more than a dozen press releases over the past eight months to generate over $1.5 million in airline ticket sales. In other words, the unique links only existed in the press releases. If someone read a story in The New York Times or Washington Post about one of our announcements, they couldn't click on the unique link, because the press rarely picks them up. We just tracked people who had read one of the news releases, clicked on the unique link in it, and went on to purchase a ticket at Southwest.com. The audience included academics, marketers for Fortune 100 companies, and vendors of various measurement services -- who are all working to find more effective ways to measure PR. So, including links in press releases can be a revenue generating tactic -- with the following qualifications. We found that when the "news" wasn't as compelling, we didn't generate the same kind of ticket sales. So, you need to optimize for more than the news search engines. You also have to write for the users of news search engines. Over 27 million people use news search engines a month, according to Nielsen/NetRatings. It is these human beings, after all, who conduct news searches, decide if they will click through a headline and snippet of copy to read the full press release, and then decide while reading the release if they will click on a link to visit your site to get more information, sign up for a newsletter, fill in a form, or order online. So, don't use press releases as a cheap link building tactic -- use it to harvest real interest in real news. Another thing we learned was to link to related or relevant content. When the link went to the home page, a lower percentage of people went on to make a purchase. When the link went to a page about the special fares or new services being announced, then we got a much higher conversion ratio. This sounds pretty obvious, but many PR people still haven't learned the basics of building targeted landing pages. Last but not least, we did some experimentation with different price levels. Yes, PR Web can get your press release crawled by Google News for as little as a $30 contribution. You will also get your press releases crawled by Yahoo News for an $80 contribution to PR Web. But, if you want your news release to be crawled by more than half a dozen news search engines -- as well as ranked high in PR Web's daily RSS feeds -- as well as ranked high in the opt-in emails sent to about 100,000 journalists, analysts, and free-lancers -- as well as ranked high on the PR Web network of sites (which get more traffic than the other press release distribution services according to Alexa) -- then you might want to consider higher contribution levels. You might even look at the combination rates for both PR Web and PR Newswire -- to get the broadest coverage. We've discovered that you get what you pay for. In other words, the higher contribution levels offer greater results. Of course, your milage may vary, so the prudent marketer will test several levels to see what works best for their product or company. One last thing we've learned: This is NOT a cheap link building program. You can get less expensive links from a variety of other sources. However, it is an incrementally inexpensive way to build links while also distributing your press release. The win-win here is killing two birds with one stone. If you are just looking for cheap alternatives to link farms, this isn't it. But, generating over $1.5 million in ticket sales for about $10,000 in news release optimization and distribution costs gives this tactic an ROI that most companies would kill for.