Twitter soaring in mobile ads.
The Twitter Inc. logo is displayed on computer monitors for a photograph in Washington, D.C., U.S., on Friday, Sept. 13, 2013. Twitter Inc.'s market debut will be the most anticipated initial public offering since Facebook Inc. listed last year, and the microblogging service is making sure to avoid some of its rival's pitfalls. Photographer: Andrew Harrer/BloombergCopyright 2013 Bloomberg. All rights reserved.