Features of WTF.
1. Statistics tracking including your battle history (all of your opponents that you've faced) as well as attack history (what attacks you've used most frequently, which ones you've used less, etc). Also includes details about each match that you've played so you can see exactly how each match occurred from the number of hits you've done to the throws you've done, etc.
Stats can also be seen according to the last 7 days, the last 30 days, etc. so you can see how your performance has been over time.
2. Leaderboards
3. World Tekken Federation Achievements - Achievements made specifically for the online service.
4. Youtube replays are mentioned so you can analyze all your matches and your performance. Assuming you'll be able to sync data through servers and upload all your matches to youtube through WTF.
5. Team system. Create your own clan of players.
6. Team-specific forums. People inside the team/clan can speak to each other.