The advantages of most Instant Message Programs are: 
 
You can be alerted when your friends, family or chat partners are online.
You can leave messages for Chat partners when they are not online.
You can receive messages from chat partners when they are not online.
You can send files, share web site information, and surf the internet together.
You can arrange a group chat so additional users of the software can join in on your chat session.
Plus all kinds of other neat interactive abilities and options.
 
When Instant Message Programs are the preferred Chat Type choice
If you want to chat with specific people or have the ability to know when specific people are online.
If you want to let specific people know when you are online.
If you want to chat with and share files with specific people.
then the answer is YES.
 
The Cost = free
Most Instant Message Programs are free! Below are some of the most common Internet Message Programs.

Instant Messenger Programs
Want to chat with a friend or family member when they are online? Download and install a Instant Message program and get them to download the same software too. You will get some cool software that will let you know when your friends are online! You can chat with them in real time, or send them messages when they are offline. Plus lots of other cool stuff. It's Free, It's Cool, It's Easy!

ICQ
 
MSN Messenger
 
AIM: AOL's Instant Messenger