Everyone put the signature into profile,Can anyone tell me Is this compulsory for merit and rank or how important for rank?
No, the
opposite is true. Many established members of this forum (including many merit sources) frown upon members with signatures. Especially members with signatures who abuse the forum with meaningless one-liners and posts of low quality. If you want to rank up and earn some merits, you have to to try to post quality posts that benefit other users. Wearing signatures in combination with posts of low quality can only potentially raise a red flag in their eyes.
What are you going on about? Why would anyone have a problem with people advertising signatures in order to earn money? It is true that the people who post low quality posts and spam like crazy raise red flags, but advertising signatures does not automatically mean that they are posting low quality posts. Check the post quality before judging. Merit system basically minimizes this problem to a big extent anyway.