Threadless allows customers to submit their own designs and to vote on which designs they would like to see printed on a T-shirt. This business uses a technique.

Crowdsourcing technique.

Explanation:

Crowdsourcing involves collection of information from a group of people that have relevant input in a subject, and is usually done over the internet. It allows business save money because the feedback is usually lowcost or free, and saves time.

Threadless by allowing people submit their own designs and vote on what designs they would like to see on T-shirts, are using crowdsourcing to get feedback and ideas from the public.