Start a local chat forum then rent out places to local businesses

I've read a lot here about creating business listing directories and then selling listings/ad space. The principle seems to work pretty well.

I have thought of creating a forum instead of just a directory - my inspiration comming from a site I frequent here. Just look at how many directory listings there are all paying 100 euros! And there are others. All this was built by forming a community forum first and then selling directory listings to its members.

I have noticed that in my city there is nothing resembling a chat forum and there are 200,000 inhabitants in the city expanding to almost 500,000 if you include the immediate areas in the conurbation.

I have checked the domiian availability and mycityforums.com/.co.uk is available. I think I could easily create a successful forum.

Why do I think this will work? Well, if a business listing directory can be successfull at getting traffic with the visitors having nothing to do on the site apart from browse local biz listings, then surely an interactive, viral forum will do a lot better. It will naturally create content, backlinks and attract traffic and the local businesses will surely find that attractive.

Here's how I would do it.

• Set up the best forum software (vbulletin) on a keyword domain.
• Install the facebook plugin that lets users log in with their facebook profile - update their wall with their posts automatically.
• Use my extensive network of family/freinds in the city to post for me to get things started.
• Possibly use forum posting service if they can do it on a local level.
• Create a facebook fan page and use facebook ads to drive initial traffic.
• Use adwords to drive initial traffic.
• grow the forum for 6 months
• Add a directory section where local biz can have a link for £20/month.

Has anyone done/doing this successfully? Are there any obvious flaws to this plan?