I’m still worried about the security of any digital media, long term. Even Kindle.
Sure, digital media might become compromised but don’t novels have a short shelf life anyway such that you might make more money than you otherwise would, AND you might get a boost for your next book sales from the additional advertising “stolen” digital copies provide.
I think the jury is still out on pirating and how that affects sales but it seems Amazon’s unlocked MP3 sales have boosted the sales of many recordings.
For me, anyway, I have purchased Amazon MP3s and have been “given” many I would not otherswise have purchased, but, that has also caused me to buy more as I think that my collection could use that next CD, so I make the purchase. In other words, I buy because I feel I have gotten my money’s worth from both legit purchases and pirated copies combined.