SAN FRANCISCO: The Horn Group has added wi-fi provider Xirrus to its client roster. The account, which has a monthly retainer in the region of $15–20,000 was awarded following a competitive, six-way pitch. Horn Group VP Erin Zehr will lead the Xirrus account. Horn's New York office also recently added Chile IT to its client list. The account will be led by principal Ben Billingsley and focus on promoting Chilean technology companies and the country's IT industry.