Sales of e-book readers are going to skyrocket - but not for a few years yet. So says market watcher ABI Research, and it's conclusion is largely backed by fellow analyst Gartner.

According to ABI, the e-book reader biz won't boom until 2013 when, it reckons, shipments will increase by almost 100 per cent on the previous year, jumping to 30m units.

Gartner has its eye on the more immediate future, forecasting that shipments will hit 6.6m this year, up from 3.6m in 2009. Shipments will jump 68.3 per cent in 2011 to 11.1m devices.

That's not so very far behind the 15m units ABI is tacitly saying will ship in 2012, before leaping to that headline figure of 30m the year after.

Both companies are united in the view that it will be sudden international interest in e-books that will propel growth two or three years down the line. At the moment, most sales take place in the US, but Western Europe is getting keen now, with the ball rolling in Asia and China very shortly.

Of course, it might all go to pot if e-book reader makers don't keep device prices on their current downward trajectory. Media tablets like the Apple iPad and Samsung Galaxy Tab are e-book readers in their own right, as are all the new ones coming in the new year.

The big question is, to what extent can firms like Amazon and Sony - the key e-book reader sellers - keep sufficient price differential with the incoming tablet horde that book buffs continue to see the benefit of a dedicated device over one that lets you surf the internet, email, watch movies as well as read books.

The colour screens coming to e-book readers over the next year or so will help, but they will also narrow the price gap between readers and tablets.

History shows that consumers do not favour separate devices over jack-of-all-trade gadgets. Look at how quickly feature phones and smartphones killed off the combination of PDA and basic voice handset. ®