This is the problem with the advice G has doled out. There is no universal definition of thin. I have pages with one sentence of content. But that one sentence helps someone looking for a particular phone number. Am I going to noindex this page or move it to another domains? Am I going to merge it and bury it among other short pages?
One sentence can be far more helpful and useful than 10 pages of content.
Don't noindex your contact page. It is a useful page! Examples of not useful pages are those that no one cares to read or would ever want to read.