If you promise to get an employee an answer, get it for him or her. If you say you'll send a team member a report, do so. As the Nike campaign/slogan so aptly says, “Just Do It.”
Too many managers don't follow through. Perhaps they get busy. Perhaps they forget. But, following through is critical to keeping your team effective and efficient. And it's necessary for gaining respect from your employees.
Following through also means doing so in a timely fashion. If you take too long to follow through, it's as bad as not following through at all.