Last Friday, I wrote about how paid content sites could take monetize editorial awards by selling the award-winning content as a brief eBook.But eBooks are not only for one-off sales — eBook subscriptions seem to be gaining some traction as a viable revenue stream for some online publishers.The UK bookstore Waterstones just announced the launch of Read Petite, a subscription streaming service for short fiction. And Amazon’s Lending Library lets paying Amazon Prime members “check-out” eBook titles without any dues dates (the caveat is that the Lending Library has only a few licenses available for its 300,000 titles).And F+W media has created a subscription service for some of its genre titles, like romance — which has rabid fans who sometimes read up to a novel a day.But, the most innovative eBook subscription service might be the one started by the Toronto Star, which is hoping to fund long-form journalism with serial content and recurring revenues. On the plus side, single-read long-form pieces are more bite-size than newspapers or magazines with many long-form pieces. The Star has already created 30 single-sale eBooks, and sold 100 to 300 copies of each (priced at $4.99). The new subscription service will be priced at $4.33/month, and subscribers will receive one new book (or “dispatch”) a week.And there is some precedent for modest revenues from long-form articles via eBooks: Wired was able to sell more than 50,000 copies of an expanded feature story on tech-entrepreneur-turned-fugitive John McAfee, garnering approximately $34,650 in revenues (after Amazon’s 30% cut).Image (c) goXunu Reviews via Flickr.