The simple answer is yes, if you want to keep your game alive. Many games have seen the amount of user’s online rise after adding an in-game chat; this has helped their game to become bigger and more successful.
User’s are more likely to stay if the game has an in-game chat which is built into [...]

There are hundreds of sites offering free chat services.
The best one in our opinion is Ipocalypse IRC.
Within 1 minute you can start your own chat and embed it in your game or standalone.
Easy to follow instructions are provided.
more info at http://ipocalypse.net
You can see a example of the chat embedded at http://www.cetopwebgames.com/chat.php