Pass-along readership is something publishers take for granted, be it in print form--where I dog ear some pages and hand off a magazine to a colleague--or digitally-- via cutting and pasting at some sites and email this article to a friend links at more savvy sites. As with most things digital, this has taken on exponential significance online and transformed word of mouth marketing. Today I read about a Singapore based company called Purple Ace that provides digital content discovery solutions. That's right, all these guys do is facilitate discovery (and no, they aren't a search engine). The premise is that most potential users don't necessarily go looking for content, they rely on word of mouth (or short text message as the case may be). It's Ripple Discover product allows subscribers to pass on purchases to friends, in a copyright protected environment if applicable, resulting in "snowballing." Turns out the company recently used a viral marketing campaign of its own when it launched a ringtone "competition" which it actually hopes will set some sort of record for virally transmitted content. While it isn't surprising that the company currently focuses on the mobile content market--particularly hot in Asia--the theory and practice are worth taking a peak at.