I work for a company that makes pledges
a lot. We've very much a company known for ethics and environmental issues, and we follow through on the pledges we make, so our customers like it. We (the employees) also like it. Nailing your colors to the mast and defining what sort of company you want to be can be a really strong recruitment tool. So long as you're actually capable of doing what you're pledging to do then it can work out well.
The thing is though, there's very little upside if you're a more typical business - you won't get any media coverage, your customers won't care, and you'll be tying yourself in to something that if you fail at will look pretty bad. For most companies it's a bit of a waste of effort.
