You can track topics for up to 30 days yes... but how about those stickies that you want to track that you can keep on going back to without hassle.
When you track a topic for 30 days, the thread disappears until found again or you keep on renewing the expiration date...
An easy way to fix this hassle is to have a permanently track a topic option.
If you wanted to no longer track a topic than simply click on "Unsubscribe Selected Topics".
This feature would do nothing but create less of a hassle, it is an optional thing so you can still select "Track for 1 Day, 3 Days, 7 Days, ect."