The chance to win a trip to rugged Denver or the lake-lined Twin Cities has thousands of supporters flooding the Internet and giving up their e-mail addresses and contact information in hope of joining their party’s nominee during convention week.

While such feel-good contests excite supporters, the real prize is for the parties, which collect thousands of new e-mail addresses out of their marketing ploys.

“Obviously you want to generate enthusiasm within your base, but it’s also a great way to get more e-mail addresses,” said Josh Schultz, who recently served as the new media director at the National Republican Congressional Committee. “You have to fish where the fish are.”

Democrats are baiting their supporters with an all-expenses-paid, four-day trip to Denver. The winner will be selected at random. In an online banner of mountain peaks and block letters, the Democratic Congressional Campaign Committee asks supporters to submit their name and e-mail address for a chance to win.

While the contest does not require a campaign donation for a chance to win, participants who give up their e-mail address could be hit up later in the campaign season. The DCCC has collected more than 10,000 e-mail addresses from the marketing approach.

“Throughout this cycle we have seen an unprecedented increase in our online participation, and we wanted to harness that energy and ensure our supporters had an opportunity to experience the moment firsthand,” DCCC spokesman Doug Thornell said.

The DCCC, which kicked off the convention contest in April 2008, relaunched its Web site last year and has used giveaways to build a growing e-mail address list that is now 3 million strong. The committee promoted a chance to win a strategy session with Democratic operative Paul Begala last year and has pushed several other contests this cycle to attract new supporters and charm existing ones.

This year, the Republican and Democratic convention committees are also dangling trips to Denver and Minneapolis, co-sponsoring video contests with YouTube, calling on supporters to submit entries answering “Why are you a Republican (or Democrat) in 2008?” Courting fresh inspiration from the party faithful, Republican National Committee Chairman Mike Duncan cheerfully calls on supporters to “be as creative and as compelling and as positive as possible” in an online spot advertising the contest. Democratic National Committee Chairman Howard Dean offers a similar pitch to woo entries for the giveaway.

An early Republican entry from 15-year-old Logan Burgett of Illinois — set to Van Halen’s “Right Now” — plays like a highlight video for the GOP. The ad could even help Burgett’s favored candidate, Sen. John McCain (R-Ariz.), combat charges that he is too old to serve in the White House.

“I’m a Republican right now because of Republicans of the past, like Ronald Reagan,” the young Burgett says in his 60- second spot. “Right now is the time to elect John McCain for president,”

The deadline for entries was Friday, and the public will begin voting on the winner this week. Legally, the convention groups cannot share the contact information they collect from the contests, but they do benefit from increased traffic to their Web sites and perhaps even a new slogan from one of the artful entries.

“Online success is not a one-step dance anymore,” said Schultz, who recently joined the NJI Media Group as the vice president of online communication, promising more online gimmicks to come. “They’re only the beginning.”