I agree with all these ideas. If it is not a charity that you want to donate to, there is always a polite way to decline.
We are a military family, so our "genre" of charities that we donate to is always ones that benifit our soldiers, like the Wounded Warrior Project, Operation Homefront, Wish4OurHeroes..etc.
I happen to be the Special Events Coordinator for the TN/KYchapter of Operation Homefront. Part of my job is soliciting as many donations as I can, in order for us to better assist our families. Last year I planned a HUGE event where we filled 500+ backpacks with school suplies and handed them out to our Military kids. I had many vendors donate things, such as bouncy houses and popcorn machine, etc. We have a charity here called "free cakes for kids" who will graciously donate a cake to a military child that otherwise would not receive a cake. I contacted them about my event, and let me tell you....they blew me away!!! I had them lined up at the door donating sheet cakes, cup cakes, cookies, cake pops etc. They gave so many people such a great treat that day! So I guess if I look at it from the perspective of somebody on the receiving end (not the business side), if it is something you can truely put your heart into it...DO IT!! Regardless if you get any business out of it...you may still be touching somebody that day in a way that is worth more than the time and effort you put into your donation.