I'd consider at least 6 members who post at least 1 time per week as activity.
Okay! So to sum up, this is your guiding light:
- Focusing on your advertisement forum
- Goal for success is "activity"
- Specifically, a minimum of 6 members who post a minimum of 1x/wk
Next, you need to come up with a plan to facilitate that. Member-oriented activity tends to require the following three things: 1) reaching your intended audience; 2) converting guests to users; 3) retaining active users.
Reaching Your Intended AudiencePerhaps a little ironically (or fittingly, depending on your perspective) for the subject of your forum, the primary way to reach your intended audience is through various forms of advertising. Ad posts in active communities that have space designated for advertisements is great for increasing your chances of reaching people + increasing your SEO legitimacy. Similarly, affiliations do something very similar, but affiliations tend to have an extra level of responsibility in that you need to follow each forum's requirements for affiliation (which is usually centric to forum activity, age of your forum, and the subject matter) or risk having the affiliation revoked or rejected.
If you're so inclined, you can also utilise social media to help increase visibility. This isn't a for-sure way since social media also needs additional work to make sure that your social media presence is solidified, but if you already have an existing social media account with at least some sort of follower base, it could be beneficial to advertise your forum there.
Lastly, SEO is going to be really helpful here if you can manage to orient your thinking around it. There's a help article on [
Understanding SEO] here on PB's help guide, but in addition to this the key is
organic content. Instead of spamming keywords or links, it's a slow-and-steady approach where you create content that naturally discusses the subject of your forum (forum advertisement). This is going to be a long-term investment; PB as a software is optimised for SEO already, but you'll need to be the one to refine it and take advantage of that optimisation.
Converting Guests to UsersThere are a lot of ways to convert guests to users, but the key thing for forums is creating a
need for it. This is, I think, going to be a very difficult path for you considering the subject of your forum. Most people who would use a forum to advertise their own forums do not want to jump through hoops to do so (this is why other forums with advertisement areas make them guest-friendly), and so if they were to come across an advertisement forum that requires membership to post an ad, many of them will simply not post, and refuse to join.
What you need to do is identify what you're offering
in addition to allowing people to post an advertisement that would convince them to join. What sets you apart from other forums that do the same thing / have a section to do this thing, that will make it a
worthwhile use of time and investment to join your forum? What are you offering that sets you apart from other forums that
need a long-term investment? Basically, why should someone join and be
part of a community instead of just leaving an ad and going?
I don't have answers for you. Personally, I've never really found a use for an advertisement forum, but then again, I'm not invested in advertising my forum too much, so I'm not your intended audience. You're going to have to figure this out for yourself.
Retaining Users and Encouraging ActivityIf we assume that you manage to find a way to encourage guests to register, the next hurdle you need to overcome is convincing them to stay and invest time on a regular basis. You need to come up with something -- beyond just posting an advertisement to a different forum -- to create and foster a community spirit. A really good example is the forum RPG-D; this is a non-PB forum, so I won't link to it, but the basics is that RPG-D serves as a hub for all RPG forums (the "D" stands for Directory). They've built a community for RPG forum admins by creating content and discussion areas for the things RPG forums need the most: advertising for specific character needs, sharing resources (art, coding, etc), filling art/coding requests, etc, IN ADDITION to the actual directory itself.
Similarly, you need to figure out what it is you're going to do to keep these folks active. Your goal is for members to post a minimum of 1x per week. What should, or could, they be posting? If you only want them to post an advertisement, the activity is going to not sustain itself because you're not building a community or encouraging interaction. Looking at your ad forum, as a guest, there seems to be nothing beyond posting an ad. Again, why would a user stay here?
Closing ThoughtsThere is no "secret sauce", no magical single solution that's going to create a forum community out of nothing, so you'll need to work very hard -- a lot of patience, time, and trail + error will be required. If this is what you want to do, then you need to commit. It won't be fast, and it definitely won't be easy, and there is no guarantee of success. The real formula is just working hard, trying, being consistent, being patient, and having some luck.
Hopefully this is helpful enough to help you get going; please let me know if you have any questions!