Do all companies pay Dividends?
No. Some companies pay dividends while others do not.
Apple, Inc. (NASDAQ: AAPL) pays them VERY rarely (and never while Steve Jobs was in charge), instead opting to retain their earnings for future use. This strategy led to a point where during the summer of 2011 Apple, Inc. had more cash ($76.2 billion) than the United States government ($73.77 billion)! (Source: CNN, Wall Street Journal).
Other companies do not pay them at all. Berkshire Hathaway (NYSE: BRKA) has never paid a dividend, instead reinvesting their profits. It's hard to argue with Warren Buffet's plan however. In July of 2012, the stock of Berkshire-Hathway was selling for over $125,000 FOR ONE SHARE.