Promises

I've noticed a lot of bloggers have been making promises that at some point or another they're gonna have to break. Three of the four people I follow have miraculously posted that they'll post everyday, or make a review on one specific day of the week. How can they possibly know that there aren't going to be inconveniences, such as the internet going down in the area, or the person's laptop/computer breaking down? And anyways, don't people say that a resolution is more likely to be kept if the person keeps it to themselves? I make commitments to this blog, but I have more of a chance at keeping them if I don't brag about it to my readers.