Duotrope have just announced that they will be ditching most of their free features in the new year. After that you will need to pay a subscription of $5 a month if you want to be able to search their listings or use their submission tracker. So if you use their system to track your submissions and you don’t want to subscribe you will need to back up your data before the end of the month.
Duotrope is a useful resource, but I have never used their submission tracker and I can find market information elsewhere, so I will not be subscribing.
You can read their announcement
HERE. (The page has been moved/removed)