I honestly think it all depends on what kind of forum you have. A promotion forum would be weird with a rule saying no advertising your site, whereas a horror or a specified RP niche would be fine with a rule stating no advertising in your signature.
I, however, dislike it all together unless it's a nice pretty image that doesn't blow up my screen. I see people with so many links in their forum, plus a giant image itself, it just get's crazy.
I have done it to where you can only advertise your site in your signature as long as the link redirects the user to their promotion directory thread, that way it's an "approved" site (looky there, I sound all mini-modish now) and our mods don't have to worry about combing through the sites linked in someones signature to make sure it has suitable content.
Basically it depends on your forum. If you do allow advertising make sure you note that the sites linked in their signature have to abide by your global guidelines, though. 😉
I think signature is allowed in all forums. The only difference is that some forums offer signatures from the first post, while good forums often allow them after you have a good forum post count.
Advertising in your Signature should be allowed after so many posts and days of membership. But like Lunar Souls said It depends on the niche of the forum.
Links in sigs are more than enough. Even a small banner which isn't too distracting. A post requirement should be put in place to enable it for users, because new members woud just join for advertising and not contribute any content to the forum.
Would you guys be aggravated at a forum not allowing any type of advertising? I paid for the software that I'm using for the forum I'm building, and am considering not allowing free promotion for other people, you know? It's a graphic art & design forum, not an ad board. There will be NO integrated space to advertise, I'm just debating the signature stuff.
Signature advertising only really pays off if you contribute to a community enough to be seen as a value, active, and likable member. Since that is what admin's want members to do, I think it's a fair trade. You make content on their forum, and add to their community, and in exchange, you get to have a couple signature links.
Although, the reason this is often banned is that some people don't see that truth of the matter. They think someone will click their link if they post a lot of garbage posts. The truth is that people will only click their link if they like them as a person. At least, that's what I've largely seen. Maybe some quality click-bait might work, but when I click on someone's sig link, it's because I wonder what else that person is up to.
I think it depends on the type of site. For example: If an admin creates a site about writing and is looking for authors to participate, then that site might allow the users to advertise their author sites and pages in their signature but disallow any other links.
A promotion forum, however, shouldn't restrict their users from advertising in their signature. That being said, a limit can be enforced to make signatures lose overwhelming look and feel of countless ads.
I think a small line of text with the url and a little information is fine, though I've seen size 200 bolder red flashing text in users signatures before which I think should be an absolute no-no.
If its someone I know on a forum. I would join their forum if we're well acquainted. But if they only joined to promote their forum and are hardly active, they can forget it.