On my commute to work, I am astounded by the number of people whose eyes are glued to their screens. Increasingly, many of us are not on our smartphones or tablet PCs, we're reading e-books on various devices, including Amazon's Kindle or Germany's answer to it, Tolino.

About five percent of Germans own an e-book reader, and nearly 2.5 million plan to buy one within the next two years, according to a study commissioned by the Allensbach Market Media Analysis. The figures may be encouraging for publishers hoping to cash in on the growing market.

But consumers beware.

The basics

One of the most important things you need to know about e-books is that you don't own them. You may have paid money for them, but all you've bought is permission to download and read them.

Most e-books are loaned to the user - and exclusively so, for use on the device on which they are downloaded.

E-books tend to come with digital rights management (DRM). As in the music industry, publishers and retailers use DRM to prevent you from using your e-books on multiple devices, or copying and sharing them.

The publishers and retailers say this is to stop people infringing copyright laws.

"I guess most people who use e-books occasionally don't know about DRM," says Yvonne Uelpenich, who works for German e-publisher Bastei Entertainment - one of the few e-publishers in Germany that sells e-books without DRM.

"But they have to decide whether they're okay with DRM or not - quite early on - because when they choose their hardware, the e-book reader or tablet, they're making that decision."

So if, for instance, you decide to buy a Kindle or the Tolini, you will only be able to read e-books with DRM from those stores.

The problem is that most retailers who sell e-books with DRM do not communicate this openly, Uelpenich says.

"Why would they? Because it's obviously a disadvantage," says Uelpenich. "But there are also a few platforms that offer e-books with DRM and without DRM, which they only communicate on the title pages."

"This is because they can't openly promote their DRM-free e-books without adversely affecting the publishers that use DRM."

No incentives for retailers

And things are unlikely to change soon. This is in part due to the design of the most popular devices on offer.

"That's because Apple or Amazon are unlikely to change their whole product range - and they're using DRM," says Uelpenich.

One other reason why it's hard to change the current situation has to do with taxes.

In tax terms, says publisher Sebastian Posth, e-books are handled as licenses and services, rather than objects.

And it's hard to resell a license or service.

In email correspondence with DW, Posth says this tax arrangement plays into the debate about whether users should be allowed to resell their e-books - currently, retailers' terms and conditions tend to prohibit the reselling of e-books.

"But [what if we change this tax situation], would that mean that users are allowed to resell e-books?" Posth asks. "And what about DRM then?"

In November, there was an attempt in France to encourage retailers to sell non-DRM e-books by taxing them at a lower rate than e-books with DRM, but the move was quashed.

Bastei Entertainment's Yvonne Uelpenich doubts there'll be any such efforts in Germany. And even if there is such a move, Uelpenich says she doesn't believe it will help book buyers.

"If there was a higher tax rate on e-books with DRM, they would probably just demand a higher tax rate from the publishers, who would then have to increase the prices for the consumers," says Uelpenich.

Do your homework

With no government incentives and a lack of a legal framework for e-books, retailers will be left to their own devices - so to speak - and it will be up to consumers to do their research before purchasing an e-book reader.

For consumers who choose not to be tied to specific retailers, there are sites online offering used digital goods and e-books without DRM for sale. Redigi allows users to legally change ownership of digital goods without illegally circumventing DRM - it's not available in every country.

German sites Beam-eBooks and Bastei Entertainment offer e-books without DRM.

And if all else fails, there's always Creative Commons.