A twintern is usually a student or a person who has recently completed their degree and is therefore anxious to gain professional experience. Twinterns are recruited by companies specifically to spread the word about brands and services on Twitter or other social media platforms. The word twinternship is also used to refer to this as a work placement, paid or unpaid and usually for a fixed period.
Instead of the usual activities that interns get lumbered with – photocopying, making coffee or other tasks that no one else really fancies doing, twinterns have an opportunity to do some very high-profile publicity work, networking with millions of potential customers.
The terms twintern and twinternship first hit the spotlight in 2009, when restaurant chain Pizza Hut became one of the first companies to officially employ someone in this type of role.(Source:macmillandictionary.com)