Is a bubble forming in the mobile app space? Ad firm Fiksu estimates the cost of obtaining a...

|By:, SA News Editor

Is a bubble forming in the mobile app space? Ad firm Fiksu estimates the cost of obtaining a "loyal" iOS app user rose to $1.81 in December, up 65% from May's $1.10. That's good news for Google (GOOG), Millennial Media, Velti (VELT), and other mobile ad firms, but less so for developers. The download volume for the top 200 free U.S. iPhone apps is believed to have grown 60% over this time, to 6M downloads/day. (previously)