The V badge is awarded to people who vote on other user's auctions. We use the voting system to make suggestions to other people and therefore votes help us figure out what people like.
We constantly keep monitoring the system. So the badge may come and go randomly.
Yes! We don't expect any selfless work. Users who have the badge will experience a slight bump in ranking, which may help you sell a little bit more yourself.
No! There's absolutely no need to worry about this. The bar is meant to help you understand better what your audience likes. We think that it's a valuable feedback mechanism to tell you what potential buyers like better.
This score is private. This means that only you can see it and you cannot see who voted what on your auctions. It is important to understand that your score does not influence your ability to post auctions or to sell.
Auctions older than 1 month lose their score. This is absolutely normal.
As you may know, you cannot vote on your auctions. Abusing the system is now allowed. There's also a limit on how many auctions you can downvote every day.