TRICK OR TREAT: Topshop is using Halloween to bring together its digital and physical worlds, with the launch of a social media competition called Trick or Tweet, invented to celebrate its debut Halloween collection “Witching Hour.” Topshop customers can enter the competition by tweeting Topshop a picture of their Halloween look, or their favorite Halloween style tip. The best tweets of the day will receive $150 gift cards and, in selected flagship stores, customers will be able to purchase items using tweets as currency in the Topshop Tweet Shop, where Halloween-inspired make-up will be given in exchange for tweets. Complimentary make-overs will be available to all customers and shoppers will be able to take twitpics of themselves with instore Trick or Tweet backdrops and posters. The best Halloween-inspired outfits seen instore during the “Witching Hour” from October 27-31 will be rewarded with additional prizes, and winners will be re-tweeted to all Topshop’s fans. An album of the best outfits will be shared with its millions of social followers on multiple platforms. The competition will be open from October 26 to 31.