Stop thinking small. Mobile is in every hand today just about and there is no shinier proof than the recent rollout of mobile banking — to a surprisingly huge membership segment – by Desert Schools Federal Credit Union, the $3 billion, Phoenix-based institution.

Desert Schools had been dithering about rolling out mobile for some years – "We knew we needed it to retain members," said Cathy Graham, a vice president who said that such plans had been put on hold as Desert Schools found itself in one of the geographies hardest hit by the recession. But when the economy began to perk up, Desert Schools put mobile banking back on its must-do list.

Desert Schools pulled the trigger this summer – uploading apps to the Apple Apps Store, Android Play, and even the BlackBerry Apps store – and 90 days later it has a stunning number to report: "30% of our online banking users are now using our mobile apps," said Graham. That is 57,000 users for the Desert Schools apps and they have been enrolled with minimal marketing push to the credit union's 322,000 members.