A Kindle 3G electronic book reader, the latest iteration of the Amazon device that first hit shelves in 2007. (Chris Ratcliffe/BLOOMBERG)

I’ve done my part to prop up the consumer-electronics industry in recent years: a flat-panel TV downstairs and one upstairs, his and hers smartphones, not-too-obsolete digital cameras, a desktop computer upstairs and an iPad 2 downstairs (well, once it gets off back order).

But one thing is missing from this electronic inventory: a Kindle, a Nook or any sort of e-book reader.

That’s not an accident. The e-book business seems determined to repeat the early mistakes of the music industry with “digital rights management” restrictions. But this time around, I don’t feel compelled to back their early investments with my own money.

Think back to how the first good, mass-market music-download store worked. Apple’s iTunes Store seemed like a revelation compared with earlier, listener-hostile efforts, simply because it let you listen to your purchases in most cases.

All you had to do was consent to listen to songs bought off iTunes only on the five computers you’d authorized with your account, plus any iPods or iPhones you owned.

Those restrictions started to grate on some users. Then Steve Jobs admitted he wasn’t a fan of DRM himself, one major label decided it could do without it as well, Amazon launched an entirely DRM-free MP3 store . . . and less than two years later, DRM vanished from iTunes, too.

Somehow, the recorded-music business did not perish. Digital sales should finally pass CD sales next year.

E-books haven’t come as far along. If you buy a title from Amazon’s Kindle Store, Barnes & Noble’s Nook bookstore or Apple’s iBookstore, among others, the DRM attached to it will prevent you from reading that book on another company’s software or hardware.

That might not seem like a problem today. Amazon makes a pretty good e-book reader today in the Kindle and has since shipped software for a growing variety of computers and smartphones. But do you trust it to lead that category of hardware and software for as long as you’d want to reread that book?

E-book DRM also disables many functions common to paper books or other electronic documents. Most stores don’t let you copy text from a book to quote elsewhere, although Barnes & Noble is a welcome exception. Printing? Forget it, unless you go to the trouble of placing an e-reader face down in a copier, one page at a time.

Lending is limited to those titles for which a publisher has authorized it and comes with condescendingly strict limits that most librarians would not recognize. For example, Amazon permits only one 14-day loan per authorized title, ever.

Reselling an e-book? Forget it.

All those limits and lock-ins make an e-book with DRM a dubious deal. Why would I want to pay almost as much as for a paper book — in some cases more — and then have my purchase constrain its usefulness and therefore cut its value?

Some smaller publishers haven’t bought into DRM, just as independent record labels never saw the point of it. Tech publisher O’Reilly and Associates of Sebastopol, Calif., sells titles on its own site and through such outlets as the Kindle Store without any “protection.”

Has the company lost any sales? In a nutshell, no. E-book sales had grown to more than 10 times print sales on O’Reilly’s site by the end of 2010, wrote Vice President Andrew Savikas.

The mainstream sites are showing some signs of being open to removing DRM. Amazon, Apple and Barnes & Noble now all allow publishers to opt out of DRM. Apple even defaults to omitting DRM, although it takes only one click for a publisher to restore that.

But good luck finding out whether a potential purchase comes with the usual digital locks. Apple and Barnes & Noble provide zero indication of an e-book’s DRM status in their stores. On the Kindle Store, you might get lucky and find that a book’s title notes that virtue, or that a publisher has thought to tag that page with a “drmfree” label.

But most publishers don’t give their own authors that option. My colleague Joel Achenbach’s new book “A Hole at the Bottom of the Sea” sailed into the Kindle Store with DRM intact because he never had a choice — he was never asked. His agent, Michael Congdon, said major publishers don’t negotiate that.

Maybe most authors would choose DRM anyway. Dan Pacheco, chief executive of Boulder, Colo.-based BookBrewer, wrote that his Internet-publishing startup will provide an author’s work without DRM, “but no author has done that to date.”

There is one way to settle this discussion. Give customers a clear choice, let the market work, and the book business might discover that it can read the recording industry’s sheet music.