If you've attended a tradeshow, you've probably left with a bag packed full of promotional products, business cards, and sales collateral.

We all have the best intentions when we add something to our swag bags, but the reality of our busy lives sets in the second we walk out of the tradeshow and get into our cars. Materials collected at a tradeshow often get thrown out immediately or discarded after sitting in a corner of our office for months.

If your company uses tradeshows as a marketing tactic, QR (quick response) codes can help you avoid the inevitable doom of the tradeshow-bag black hole. QR codes are the square-shaped, (usually) black-and-white barcodes that we've all seen popping up on billboards, in magazines, and in commercials. When a QR code is scanned by a smartphone, it typically opens an informational Web page or video.

QR codes are catching on quickly in the US now that more than 35% of American adults own smartphones. In fact, QR code usage shot up 4,549% in Q1 of 2011 alone, with 9 out of 10 scans being done to find more information about a product or service.

So, how can QR codes help you make an impact at a tradeshow?

1. Skip the business card

A QR code can store your contact information so that scanning it with a smartphone creates an entry in the smartphone's address book. Stick your personal QR code on your tradeshow name badge (print it on a label), and encourage new business contacts to scan it to ensure your business card doesn't get lost in the shuffle. It will also help your new contact recognize your name when you make a follow-up call after the tradeshow.

2. Stop wasting paper on marketing collateral

Companies love decorating their tradeshow tables with dozens of flyers created by the marketing team to promote each product or service. When new potential business leads scoop-up flyers and add them to their overflowing swag bags, we get excited about possibly scoring a new lead. But how can we know what the passerby does with our flyer? Does she read it? Share it? Store it? Throw it away?

Instead of distributing hard copies of marketing materials, you can distribute electronic copies via email. Simply create a QR code that triggers an automatic email when it is scanned by a smartphone. The email can contain a preformatted message from your company along with links to your sales materials.

QR codes are a great solution for marketers because your materials will escape the clutter of the tradeshow bag and make their way into your prospects' email inboxes, all the while helping you cut down on the cost of printing and transporting sales sheets.

Depending on your in-house technology capabilities, you could do one of the following:

1. Contact a QR code hosting company and ask about all-in-one solutions.
   
2. Link your QR code to a data-capture landing page linked to your email marketing software. Include a few simple fields for the user to complete—such as name, phone number, and email address—and sync the form with a subscriber list that automatically sends a welcome email.

3. Don't force people to visit your table

You don't need to limit your use of QR codes to your table display. You can include your QR code in your tradeshow directory ad, or print it next to your logo on the event signage. That is particularly effective if you are sponsoring a luncheon table and get to put signage in the centerpiece. You will have a captive audience at the table who might be curious about your QR code.

Before you use a QR code, you should keep a few key things in mind.

1. QR codes should be generated using a shortened URL. The longer the URL, the denser the QR code. The denser the QR code, the harder it is for a scanning app to read it.
   
2. QR codes don't always scan the same way across every smartphone platform, so make sure to test it on an iPhone, Android, and BlackBerry before you launch.
   
3. When you are testing, take into account the distance that most users will be scanning your code from. Is it going to appear on an event banner? The back of your booth? On your table-top display? The farther away the user, the larger the code needs to be.
   
4. QR codes don't need to appear in black and white, but darker colors definitely work better. Steer clear of pale colors, such as yellow and pink.
   
5. Not everyone knows what a QR code is, so you might consider adding a line of instructions and a recommended QR-code scanner.

Consider contacting a QR code hosting company that can create and test your code across multiple smartphone platforms and recommend the size needed based on your intended usage. By using a hosting company, you can access detailed usage statistics and guarantee the QR code will continue working as expected throughout the life of your campaign.

Free QR code generators are popping up online and can be tempting to use—especially if you are on a budget—but if your QR code doesn't work the first time someone tries to scan it, the effectiveness of your campaign will start to decrease.