It's an excuse to travel
It would be ridiculous to fly hundreds of miles across the country to participate in the Brooklyn 5K, but it's not as crazy to come from far away for something like the Brooklyn Half, for example, which involves a seven-day pre-party with local artists and food vendors. “There’s entertainment all day long and into the night, and it’s very much a collective of the community,” Ciaccia describes. “It gives you the whole flavor of Brooklyn.”
After the week-long throw-down you get to shake off your hangover and put on your sneakersYou do it for an opportunity to get to know an appreciable 13.1 miles of a pretty cool borough, and to run alongside more than 25,000 people in what in 2015 was the largest half-marathon in the country. Even better, you're not totally wrecked after completing half of a real marathon, so you can actually spend time enjoying wherever your race was held.
The 13.1 mile distance is also an excellent one for dressing up for a themed race -- long enough to flaunt your attire, but short enough that you may not feel the need to tear off your Jedi costume because you've sweated through it. Runner's World publishes a list of US destination marathons that feature breathtaking views, Star Wars characters, pirates, and more. Try that with a full marathon, and you're simply a novelty character, a fun distraction among a crowd of serious runners.