Pinterest has more than 13 million users and wants to hear from each and every one of them.

The image sharing network’s staff is encouraging pinners to share their stories by promising free Pinterest T-shirts to every person who responds this week to tell Pinterest “why you pin.”

“From planning a ‘Pinterest Party’ with your friends, getting freelance gigs, building a shelf, making new friends, renovating your house, growing your business, cooking a meal, taking a trip, to stories we’ve never imagined - whatever it is, we would love to hear about it and let you know how excited we are to be a part of your story.”

The announcement doesn’t specify how Pinterest plans to use pinners’ stories. It may just be market research, but it’s also possible that they’ll be featured on the official blog. Updated regularly throughout 2011, the blog’s content slowed during Pinterest’s most extreme period of growth.

However, the simple gesture of this announcement is significant.

Earlier this year, Pinterest received criticism for being notoriously difficult to reach. Even during scandals like the Skimlinks accusations and questions of Pinterest’s legality, Pinterest CEO Ben Silbermann only interfered after panic became widespread.

True, Pinterest is seeking feedback in a way guaranteed to generate almost exclusively positive responses, but the t-shirt giveaway does mark a 180-degree spin in Pinterest’s responsiveness. Instead of refraining from user engagement of any type, the network is openly encouraging feedback.

Has Pinterest had a change of heart? Doubtful. We’d guess they only now have gotten enough people on staff to meet the needs of their massive user base.

Photo via Pinterest