Google Searches for Role in App Age

Its name has become a verb meaning "to search," but as users shift to mobile devices, Google is suddenly faced with the threat that its search engine -- and its advertising business -- are becoming less relevant.

The company was built with the help of an army of "spiders" deployed to crawl the Web, and sophisticated algorithms to rank the value of pages. But in the mobile age, those spiders can't easily navigate the apps where users are spending most of their time, threatening Google's roughly $50-billion advertising business.

In response, Google in the fall launched an initiative to better see -- and direct -- what smartphone and tablet users do on their devices. The effort seeks to mimic what Google built on the Web, with an index of the content inside mobile apps and links pointing to that content featured in Google's search results on smartphones.

[March 10]