It’s practically a rule: The journey from idea to marketplace takes longer than expected, costs more than budgeted and saps more energy than entrepreneurs knew they had – which explain why most ideas don’t move beyond the brainstorm.

But what if a great idea could go from cocktail napkin to concrete business plan in just three days?

That’s the premise for the fifth Charlotte Startup Weekend Jan. 25-27, a 54-hour frenzy designed to connect aspiring entrepreneurs with the people and resources they need to make their mental plans a reality.

Jack Dietrich, one of the event’s biggest success stories, entered Charlotte Startup Weekend 2011 with no technical background, no connections, no funding.

A year and a half later, he’s commandeering product development and raising capital for his start-up, TagSeats, a social event platform that uses digital seating maps to show potential ticket-buyers where their friends’ seats are.

The idea for the business arose when Dietrich, a University of South Carolina student, was buying tickets for Gamecocks football: “I was trying to buy tickets ahead of time, but I couldn’t figure out where people were sitting to buy tickets near them.”

Concert-goers know it well, too: It’s common to purchase tickets individually and try coordinating with friends, but nevertheless end up not sitting together.

Here’s how TagSeats.com helps: Users log in with their Facebook or Twitter usernames. They’ll see what events their friends and others are going to, and where they’re sitting. Fans can then click through the interactive social seating maps and buy available tickets near people they know. If they’ve already purchased tickets, they can enter their seating info to add themselves to the maps and encourage others to join them.

TagSeats is free for users, and makes money by licensing the interactive social seating maps and data to ticket-sellers, be they websites or apps. Now in private testing, TagSeats is scheduled to soft-launch in February.

Charlotte Startup Weekend was the starting point for TagSeats, says Dietrich, 31, who at the time was 70 miles away, finishing his MBA/JD degree from USC Columbia.

Anyone with an inkling of a business idea can pay $99 to attend the weekend-long event, hosted by local start-up hub Packard Place. The Charlotte event is run by the global nonprofit Startup Weekend, headquartered in Seattle.

On Friday night, each aspiring entrepreneur gets 45 to 60 seconds to pitch his or her idea to the group. After the pitches – sometimes as many as 60, organizers say – the group votes on the four or five top ideas.

On Saturday and Sunday, teams of volunteers work to build the ideas. On Sunday afternoon, each of the top groups presents its business plans to the audience, which votes for its favorite.

That’s how it worked for Dietrich, whose Friday night elevator pitch in 2011 won over the audience. The winners then solicited volunteers, based on their business needs.

“They stand up and say: ‘To go along with my idea, I need an HTML coder, a marketing guy, someone who knows business-to-business sales ... whatever they need,” recalls Dan Rosselli, founder and CEO of Packard Place.

Dietrich gathered a team of tech-minded business people, including a couple of developers with Fort Mill-based company Muzak, a commercial music provider.

Over the course of the weekend, the team worked nearly 25 hours to build – from scratch – a business plan for TagSeats.

On Friday night, they made a game plan. On Saturday morning, the developers created a basic digital framework, while the non-techies brainstormed useful features to offer.

Then came the Sunday afternoon audience vote. Dietrich’s plan came in second place.

Not every business that goes through Startup Weekend makes it big, says event organizer and Charlotte resident Jim Van Fleet, who founded and runs a local web-app consulting firm called “It’s Bspoke.”

But every person who attends the event will leave better connected with the start-up community and more educated on what it takes to build a business.

“And if you (win), you’re going to have some pretty strong opportunities,” said Van Fleet.”

One week after the event, event sponsor Carbonhouse, a Charlotte-based website and social media development company, partnered with Dietrich in his TagSeats venture and eventually took on an advisory role.

Six months later, Dietrich recruited a developer who had worked on the weekend’s first-place team after the creator decided not to move forward with the idea.

TagSeats now has two full-time employees and one part-time employee. And though he hasn’t been able to take a salary yet (all capital has been poured into the technology development), Dietrich has high hopes for the upcoming beta launch.

The man who attended Charlotte Startup Weekend 2011 with no connections or concrete plans is now spending time in New York City to work with former New York Jets vice president Matt Higgins. Higgins is working with Miami Dolphins owner Steve Ross to build a sports and entertainment company.

Dietrich says that people who are hesitant to attend startup weekend for fear someone else will steal their idea, are looking at entrepreneurship the wrong way.

“It’s not the idea that’s the success; it’s the execution,” says Dietrich. “The idea is the 1 percent and the execution is the 99 percent. ... If you’re afraid to share early on, you’re never going to meet the people you need to.”