Two weeks ago, I wrote about how to save journalism, advising that some sections of newspapers — like sports — should be broken out into separate digital subscriptions.At the time, I thought that was just my clever idea, but it’s highly likely I got the idea from this promotional email I skimmed from the Guardian:

It’s hard sometimes to know where good ideas come from, but the Guardian is definitely onto something with this idea. Sports fans are the most enthusiastic consumers of anything related to their passion and definitely don’t want to miss anything — they want obsessive coverage, and will pay for it.The Guardian is smart to give subscribers the option between Kindle and iPad platforms. However, marketers and publishers should know that there’s likely to be a big difference in conversion between these two platforms.This is because Kindle incorporates a 14-day trial into all of its subscriptions, automatically charging a subscriber’s credit card after the trial is over. They nicely inform customers of the terms of service through an overlay on the site after a prospect clicks on a text link for “details” (see below).

Apple, however, is not such a convenient platform for publishers looking to monetize their content through iPad subscriptions. Apple forces publishers to create two apps — one free, for the trial duration, and another paid one. That makes for a confusing conversion page on the iTunes store page. (See how the Guardian’s app is listed as free? It’s only when you scroll down you see there’s another app listed at £9.99. But what consumer would sign up for this when they’re getting a free app? Potential subscribers are likely to get confused, thinking the app is free and then getting annoyed when their trial is over.)There is a way around this. If subscribers sign up for a digital subscription through your site, you can offer them an add-on iPad or iPhone subscription at no extra price (and Apple will also let you keep the revenues since subscribers were not converted through the Newsstand store). But this is a bit trickier to do when you’re separating out subscriptions to your newspaper’s sections.Bottom-line: Automatically opting trial-takers into a subscription at the end of a trial can rocket your conversion rate from 4% to 30-50%. So Kindle subscriptions are likely to have better conversion rates than iPad editions, and therefore more revenues for your company.