I haven't learned about signatures yet. and I think this light topic helps.
but what is the signature itself used for?
To add to what everyone else have said, your signature space is a space that you can either use to advertise your goods or services, or you can choose to sell your signature space to someone else who wish to use it to advertise his or come product, goods or services, you can get payment on a weekly, monthly, or on a set period of time bases, depending on the type of person or company you sell your signature ad space to.
But it's also worth knowing that there are rules you must obey if you choose to sell your signature ad space to other people, not obeying this rules will lead to automatic forfeiture of your payment for that week or month, and if you disobey the rule multiple times, you can be removed from that payers payroll.
I believe as you advance and start using your signature ad space, you will know all that you need to know.
are we free to apply any signature?
Yes, we all are free to apply any signature, but it is important to know that your forum rank plays a huge role on the type of signature you can apply, there are different signature codes for different ranks, so please take note.
is it profitable?
Depends on how you use it.
You can use your signature ad space for your own personal use, that is to advertise your own business, and this I consider profitable because more people get to know about your business and possibly patronize you.
But if you are selling your signature ad space to other businesses, then you have to know that there are procedures which you must follow to make the act profitable, this procedure are listed below..
- You must submit an application to the campaign manager of that business stating your interest in joining their signature campaign, depending on the rule of the campaign, you might be required to wear the signature and apply or otherwise.
- You must be accepted, you must be sure you are accepted into the campaign before you start working/posting while wearing that signature, otherwise, your wearing the signature will be unprofitable for you.
- You must obey the rules, and the most common of those rules is the one that tells you the number of posts you must make in a week, and those posts must meet the managers standards of what a quality post is, not meeting or obeying this rule and other rules listed in the signature campaign thread will also make your wearing the signature unprofitable.. So please take note
Good luck.