According to Forrester Research, many Web site design teams focus on the wrong things when building new e-commerce sites. Rather than ensuring the customer’s needs are met quickly and efficiently, many get bogged down in operational issues or organizational turf wars. To avoid that scenario, the research firm recommends designers build "personas," or customer models based on real-life users and how they react to the site. Here are four key criteria for building successful personas:

1. Base it on real research. Some companies think they know what their customers want and need from their e-commerce site and design to those expectations. But Forrester says it’s better to base personas on research and in-depth interviews with real customers.

2. Format it like a narrative. This means to make sure your persona tells a story. A soccer mom's needs and expectations when buying new tires for her car differ markedly from a recent college graduate's needs when performing the same task. Successful personas include details about motivations, goals and behavior.

3. Put it into channel context. Include insights into how they use the e-commerce channel, where they use it and when they opt for other channels, such as brick-and-mortar stores or phone-based sales channels.

4. Put a human face on it. Successful personas come across as real people with real needs. It's more difficult to get lost in turf wars and the needs of the business when faced with the an actual customer trying to make a purchase on your site.