Audiences are spending more time on their mobile devices to consume short news briefs, according to Web apps analytics company Localytics. But tablets are where the action’s really at with audiences spending 50 times more time accessing news apps on tablets than mobile devices.However, discoverability remains a problem for both platforms. Consumers don’t really browse app stores like Newsstand like they do physical newsstands; instead they’re far more likely to simply search for the digital edition of a magazine they like (and there have been complaints that Apple’s search feature in Newsstand has been less than ideal).Plus, the trial versions of digital apps are often insufficient for conversion (and sometimes confusing to consumers, with apps being “free to download” but paid to access content, so the iTunes store will list them as free). One solution is to create a sample issue instead of a trial.But taking advantage of tablet and mobile publishing doesn’t mean you have to create an app. In fact, Consumer Reports found that iPad users prefer to visit their website than their app.Therefore, to foster discoverability, tablet and mobile publishers should encourage word-of-mouth sharing. Most publishers interpret sharing to mean social sharing, but in fact, Localytics research found that 80 percent of content shares happen by email. (Once again, email marketing outperforms social media.)Another method of discoverability is behavioral targeting. But publishers who use this method want to be aware of regulations that let consumers opt-out of behaviorally targeted marketing. In addition, new regulations are coming down the pike for behavioral targeting via mobile devices. We’ve covered the two critical regulations you need to follow for when using behavioral targeting, but you can check out how opt-out mechanisms might look on a mobile device with this cool test drive of Evidon’s Ad Control.