Thanks up / Gratitude

I am not sure this is a question to be asked. Motivation is key to every organization. It is what differentiates a good Manager from a bad Manager, or more importantly, a GOOD leader from a BAD leader. Even if its between the employees themselves, motivation brings a whole level of extra commitment, interest, and makes it easier for colleagues to share your vision!

I absolutely express gratitude because I understand that each team member has a choice to leave or stay. I've noticed a difference in behavior from when they first started working with me and now. They are more engaged and do more without my having to ask. They are more empowered and come up with ideas that never even crossed my mind. I do it when they go above and beyond OR complete a task that made them feel uncomfortable OR they powered through a difficult time.

Absolutely. I think this is a critical factor in motivation, especially for the highest tier of resources. As a leader (I don't love the word "boss"), you often have to call upon your team to go the extra mile. To work all night, to start over from scratch, to kill a project they invested time in. An extension of this, which I'm writing a blog post on now, is also to genuinely appreciate amazing work. There is a difference between Jordan in his prime and a solid college point guard. If you have Jordan on your team (and it could be in any role, from HR to Engineer), keeping them for the long haul requires seeing the brilliance in their work and making sure they know how much you value them. I haven't done the experiment of not being this way, so can't speak to the improvements it would cause. But imho it is worth giving a shot.