Let's not take what I'm saying out of context OK?
1) Did I mention music or movies, no. Is this thread about music or movies, no.
2) Of course Apple would like be the sales leader for bragging rights but only because that leads people to buy its hardware. Apple's profits on media content pale in comparison to what it makes on hardware. Ultimately, Apple is agnostic on what media sells users on the iPad, if its books great. OTOH Amazon has nothing to sell Kindle users but books & newspapers.
3) If you recall, when Apple started iTMS, Apple did not make a recognizable profit from music/movie sales. Jobs even said it was a "loss leader."
I dont agree, the potential profit margin on eBooks is so much higher than music or movies. Really small file sizes, very low production costs compared to movies and even music. It could be a major market in no time... eBooks just need their iPod moment and thats exactly what Apple is aiming at. Imagine if they released a new Harry Potter book and apple blagged the rights to release it on the iBook Store a week ahead of anywhere else? Really serious revenue.