The eBook marketplace just got even more crowded with the entry of a major book-selling player into the market.

Borders announced this week that it too will enter the crowded field that currently has Amazon, Apple, Barnes & Noble and Sony vying for business from reading fans.

All this competition should — and we emphasize the word “should” — be good for consumers. If the market works the way it’s supposed to, the variety of options will drive down prices of books and readers. I should also force the players to improve their service with better readers, a wider selection and an easier book-buying process.

Some of this is already happening. For example, Amazon and Barnes & Noble cut their e-reader prices last month, and Sony just did the same.

The question: Are the prices of these readers being slashed because of the number of models being offered? Or is it because of the extraordinary popularity of the iPad, which has had sales that far outpaced analyst’s predictions?

Most of Borders eBooks are in the in ePub format, although some titles will have Adobe PDF and mobile-specific versions too. Apps for most devices are available either from the Borders website or through online stores that offer apps for specific gadgets.

Tags: Borders, ebooks, iPad, online store, readers