A sponsored run or walk takes place almost every weekend in my neighborhood. They tend to happen early in the morning before I am awake, but I know there was a race because of all the sample shampoo bottles, branded Post-It notepads, bank-stamped plastic bags, and free promotional pens crammed into the corner trashcans. These sponsors were present, but you have to wonder, to what end?

With the New York City marathon coming up this weekend, it's a good occasion to think about how and when sponsorship of a racing or walking event is worth doing.

For marathoners, 5K-ers and charity-walkers alike, exposure to brands comes in all shapes and sizes. This year, marathoners in New York can attend a fireworks display sponsored by Poland Spring, get a chance to win a Nissan Leaf and enjoy the pleasures of Grana Padano cheese on a five-day tour of high-end food purveyors in Manhattan. Before event day, the roughly 45,000 runners have to check in at the Jacob Javits Convention Center, where they will find a health and fitness expo with more than 100 exhibitors competing for attention. All this is well and good, but how effective a marketing venue is this likely to be?

Before committing to a race-day presence, brands need to know why they want to be there. If it's a good fit, your goals will determine whether you create an active and more expensive interaction (brand ambassadors, sampling, booths, branded vehicles, cheese tastings) or whether passive interaction will suffice (your brand on race pinnies, water-station branding, signage). If you just want to remind participants that you support their passion, this can be enough.

Then there is the "when" of engaging with the participants. The finish-line crossing is typically about something else, like surviving cancer or completing your first marathon. But there are plenty of other possible touch points that the charity or main sponsor does not control, such as the hotels, bars, restaurants, taxis, subways and busses they participants will use.

Don't forget about the spectators -- 2 million for last year's New York City marathon. Some amused themselves with the very smart campaign by Asics that let fans record Facebook videos that ran on large screens when their runners came by . The company is repeating the offline/online program this year, but now runners' can pre-record messages that will show up on their Facebook pages the moment they run by the branded screens. Brilliant. Who wouldn't remember the brand that engineered that cool connection?

What about giving a few lucky spectators a chance to watch the racers at various points along the route? You might run a sweepstakes for fans to win a seat on a bus that takes them from the starting line to the 10-mile mark, the 20, then to the finish. This might be tough to pull off in New York, but 483 marathons were run in the United States in 2010, according to marathonguide.com., and 503,000 finishing times recorded. Branding opportunities abound.

Remember that a race "aura" extends for blocks (witness, mine) -- in the case of the big marathon, many blocks. have roaming camera crews along the course to interview supporters and let them explain how they "trained" for the race while their loved-one spent all those hours doing laps. The videos could be uploaded to Facebook and YouTube in real-time and shared with the participant when they reconnect with their supporters.

Finally, if you're thinking about freebie goodie bags, keep in mind that a ton of that stuff is discarded before the runners remove their silver heat blankets. It's a safe bet that your brand will end up most visible piled into trash cans. Your brand loses its race appeal: it becomes an urban billboard that 's a symbol of waste. A smart brand can earn fans and send a city-friendly message by sponsoring a branded post-race cleanup crew. As the runners and their loved ones scatter, city-dwellers who had their lives disrupted will see the civic action as a good thing.

There are dozens of inventive ways to be present for a race. Save those left over branded pens from your trade show for … next year's trade show.