Recently the folks at 37signals started an opinion storm over the subject of personas by saying:

We don’t use personas. We use ourselves.

When writing about Buyer and User Personas, I wrote:

In developing products and creating market messages, product management must have clarity on the ideal user and buyer. The industry has adopted the term "persona" to refer to the ideal profiles of our customers.

The issue of course is that it’s better to program to a real person when you can but as vendors, we are usually programming for people who are not us. The problem with most approaches to programming is that they assume you have access to an onsite customer. But if you’re a vendor, you need to create a profile, a biography, of the ideal customer to show that we’re not programming to ourselves.

As 37signals points out, this is not a creative writing exercise. Instead the persona should be a profile grounded in market research. That’s how we know Robin the typical product manager is 32 years old, has a Dell D610 running Windows XP and Office 2003, and is always connected to the internet. This profile is based on our qualitative research with product managers as well as our quantitative research from our annual product manager survey.

Want to add some color to our research? Take Pragmatic Marketing's Product Management and Marketing Benchmark Survey for 2007.

UPDATE: Read a great post Building a Data-Backed Persona at Boxes and Arrows and Crappy Personas vs. Robust Personas at User Interface Engineering.