Traffic volumes - tough question. You'll get different answers depending upon the site and it's content, however, we tried to assess this on a level of importance in an earlier thread here [webmasterworld.com...]
I hope that gives you some pointers.
Here's some pointers for you.
Want to find something?
There is an awesome search capability for this site - simply look at the top of the screen and click on "site search."
Found a good thread?
Use the "flags" capability. At the bottom of each thread is "flag this post." Select the ones you want to follow. To find them again, simply select "flags" at the top of the screen.
Full details of these are in the "help" section, wait for it..., wait for it..., at the top of the screen.
See you around.