Thanks for the detailed insight, Bob. Since getting my eDGe and getting into ebooks, I've learned alot about publishing costs and I now better understand pricing.

My question is, though, why do publishers feel compelled to self-destruct their e-texts when the paper equivalent they've been selling for decades remain useable indefinitely? If publishers have been surviving on paper texts which some students buy every year and other students buy second hand, why would e-texts be any different? It seems that your sales come from students wanting the latest version, even if some students are using last year's version and it seems to me e-text would be no different. Or, are publishers seeing enough piracy of e-texts that they have to overcharge (dare I say, punish? ) the legitimate buyers to compensate for lost sales?

I do ask this honestly