Joh for a work oriented site that is a great idea. And you are right its very hard to get people to be actual customers in the end. But if the site is not job related or work related then its a bit different and you have to do some other original things and have some original ideas. Here are some ideas for getting people to your site:
1) Advertise on other like forums if they allow it. If not you can put a link to your forum in your signature and just be an active member. This will help some.
2) Try getting in as an affiliate with a site simialr to yours. This is a great way to improve traffic.
3) Make sure that you submit your site to search engines and make sure that the key words you use will be the words that people will type in to get to your site. For instance. My site is about metal music and bootleg trades in metal music. I make sure that these things are in my keywords as well as the word forums, discussion boards, message boards, etc. You get the point.
4) Talk to freinds you have online who have similar interests as you and similar interests as the forum you are promoting.
5) Offer something other than chit chat on your forum. This means offer possibly a contest or something else that is oriented with your forum. In my case I offer files for download like band photos & covers and basic information on the main topic.
6) Offer a general chat area. This may seems kinda stupid but alot of people would rather just hang out and chat than be totally serious all the time about the forums.
7) I have a game area & a poll area. This offers the members games & polls to come back to and see what has been posted and promotes them to post again. We have several running games that have to do with Heavy Metal for obvious reasons. Same with the polls. If some just come in and post in these areas its ok because you never know when they will be reading the forum and see something they want to get involved in and start posting elsewhere.
8) Make it like a community. After all its a forum and should be kinda like a community of like minded individuals. If they have a sense of community they are more likely to come back and post.
9) Make sure that you don't allow certain things in your forums like flaming and people acting overall stupid towards each other. This will turn off potential people who might of been great in the community but they are not interested in getting knocked everytime they make a post. Who would?
10) Make sure you have a strong mod team that posts and keeps up with the forums and make sure that your mod team you pick are overall interested in your forum and what's going on, if not your forum will go no where quickly.
The breakdown really is you need to offer more than just the forum in itself. You can offer many other things for your uses out there. There are role playing games that you can interegrate that would be great for a gaming forum if that's what you have, or there are other things that you can offer if the forum is business related all the while keeping the forum on topic. A really good thing to do is go around to popular forums and look at what they have done. See what you like and what you don't like and expand on them for your forum. Look at succesful forums and see what they all have in common. This will help you greatly when you are first starting. Or even when you want to increase membership.
Joh did you have a website for your business? If you do and you connect it with your forum this will also help traffic to your site. Doing shows has to be costly I would think or at least some of the times it may be and when you are in business for yourself its hard to spare extra exspenses.

And BTW I always thought it was just common knowlegde that you had to re-finish stone tiles (floors) and buff them out. But then again I guess not many people do realize that there's a certain amount of work that goes in maintaining ANY floooring in your home
Hope this helps someone.
MP