Fueled by the availability of affordable ereader and tablet devices, the market for ebooks is taking off far faster than many predicted just years ago.

So it’s no surprise that more than a few big companies have been looking to get a piece of the ebook pie.

The list of notable names includes, not surprisingly, many large publishers, which, for obvious reasons, like the idea of owning a stake in the companies that deliver their products to consumers.

But it has also included some major offline retailers. Last year, for instance, retail giant HMV paid £2.1m for a majority (64%) stake in Anobii, an online ebook vendor with a social discovery twist which counts three major publishers — HarperCollins, Penguin and Random House — as shareholders.

But turning the rise of the ebook into profit is easier said than done. 800 pound gorillas like Amazon are hard to compete with and trying to grab a piece of the pie may be more expensive than it initially appeared. According to paidContent’s Robert Andrews, between two digital investments, one being Anobii, HMV lost £1m last year.

So today we learned that HMV is selling its majority stake in Anobii to another big retail name, Sainsbury’s, for £1. The price makes it looks like Anobii may be a dog of an investment, but that’s not the case as Sainsbury’s sees it. The company’s press release quotes Sainsbury’s Head of Digital Entertainment, Mark Bennett, who explains:

Anobii’s innovative use of social media is a clear differentiator. This acquisition is a valuable addition to our digital portfolio and shows our commitment to becoming a key player in the digital entertainment market. It further demonstrates how we are constantly looking to innovate and seize opportunities that will support the future growth of our business.

The big question, of course, is just how much it might cost retailers like Sainsbury’s to become key players in digital markets like ebooks. HMV obviously decided to cut its losses; we’ll soon see if an initial investment of £1 makes the endeavor any more fruitful for Sainsbury’s.