4. You have a thing for bling.
Many races include all kinds of perks and amenities to draw runners to the starting line. One such amenity is the ubiquitous race medal. The bigger the race, the bigger (and gaudier) the medal you'll typically receive at the finish line. Medals now double as coasters, bottle openers and more. If you complete more than one half marathon in a particular race series (for example, the Rock 'N' Roll Marathon Series), it's likely you'll get a special medal for your multiple efforts. So, if you've got a penchant for the bling, half marathons will hook you up.
5. You're contemplating ramping up for a full marathon.
Before signing up for a full marathon, you should probably have at least one half marathon under your belt. You can run most of the 13.1 miles at your target marathon pace and gauge how far you are from swinging this pace for 26.2 miles. An alternative approach is to go for broke and use your race result to project a theoretical marathon time. If you've never participated in a race, and a marathon is on the calendar, a half marathon can be a nice dress rehearsal for the full.
6. You want to recover quickly.
It can literally take weeks to fully recover from a marathon. It's not uncommon to feel a bit flat, fatigued, and a bit off long after you've completed 26.2 miles. The half marathon is taxing, but even if you run a hard half marathon, the recovery window for 13.1 miles is much shorter than that of the full.
7. There is less injury risk with a half marathon versus a full marathon.
Injuries are the bane of any runner's existence. One of the big factors that contribute to running related injuries is training. To be more specific, overtraining increases the risk of running related aggravations and injuries. The higher the weekly mileage generally the higher the risk of running related. Needless to say, you're not going to log nearly as many miles gearing up for a half marathon versus a full marathon.
More: How to Run Injury-Free
8. You like to party.
As mentioned earlier, the perks and amenities at races today are staggering. Aside from the gaudy 'bling' one typically receives, there is almost always some kind of post-race party or celebration. Destination Races sells out all practically all of its wine country-themed events to some degree because of the post-race wine tastings following the race.
The anti-oxidants can speed recovery and augment the runner's high. Live music often accompanies the imbibing of said anti-oxidants. If you like to party, the half marathon may be your distance.