Twitter...Good for Business?

We know that on Facebook businesses can post things as long as they want. They can get into their specials and upcoming deals, post about current events, and many other options. On Twitter, you are limited to 160 characters. Is this good for businesses, or bad? The purpose of a Twitter for business is to update and "tweet" frequently so it shows you are active and have a strong social media presence. You can gain a lot of clout by getting "retweeted" and more and more people begin to see your short post. Dog Central comments on people who tweet at them, and they post several times every day. This makes people laugh and feel "cool" when they get retweeted or commented on and it makes them want to go there even more. Is this true for all businesses? I am not so sure. Twitter is a different type of social network because it can be used in so many different ways. I like it more than facebook personally because facebook got annoying with very long posts by the same people every single day. What do you guys think is the best avenue for businesses? Twitter, or other social networks?