This document discusses the development of zooplus, an online pet supplies retailer based in Europe, from its founding in 1999 to becoming a "unicorn" (privately held company valued at over $1 billion) by 2017. It outlines zooplus's growth in three phases: establishing the business model from 1999-2004, expanding across Europe from 2005-2010, and establishing new competitive rules from 2011-2016. Key highlights include growing sales from €5.7 million in 1999 to over €1 billion in 2016, expanding to 17 European countries, and achieving strong customer retention and cost leadership. The document argues zooplus has significant room for further growth given the large size of the European pet supplies market.