If you were the NSA and “asked” Amazon.com for my order history, you would discover that I almost never pre-order anything. I am not an early adopter. I like to let other people sort out the bugs and kinks before wading in.
Why pre-order? Well, one, won’t you feel stupid if they run out? You will. Two, pre-orders can help those “bestseller” list numbers, depending on the list and how they tally things up. Robust pre-order numbers certainly are good for the author’s fragile psyche. Three, you will probably forget you ordered it by April. So, when it arrives, it will be like Christmas in April – four months late or eight months early, depending on the kind of person you are.