Getting visitors and earning money through directory based websites

Niche directories can work... but you need to put the effort in. The directory has to be value-add - it must not just be a company name and address. The other answers here have mentioned content but we really need to stress this - you need good, unique, flavoursome content.

With content comes rankings, with rankings comes traffic, with traffic comes ad revenue...
With content on each company that Google isn't seeing elsewhere, your pages will begin to rank and drive more traffic to your site. Don't expect to sell any advertising space until you have first page rankings on Google (ranking for niche long-tail keywords are ok if there are enough of them).

Content ideas... use Mechanical Turk (cheap, lower quality) or eLance (pricey, better quality) or someone to do writeups on the companies. Focus on a sub-category to start with. Also put in place any feature that encourages user-generated content - i.e. reviews on the company, comments, testimonials etc. The more work you do to add value to the company listings, the more trusted, authoritative and better ranking your pages become. Allow the company itself to edit it's pages and add more content. For free.

Remove barriers... while you are ramping up don't put any barriers in place. I know you want registered users, but by putting up a sign-up process in the way of a visitor seeing the contact details for a company is a sure-fire way to stop them returning to your site. Don't hide the information. This is also bad from an SEO point of view - if Google can't see your content you won't rank. No traffic. Bad. People want instant gratification on the web - not a good idea to put a sign-up in front of information they can get by just clicking 'back' to their Google results and then just clicking the next result down.

Good luck.

You can do pretty much nothing. Web drectories are a bad business to start with - cheap to do, no search engine content, and most websites have their own pages. Google / google maps are your competition, well known etc.

What is your niche? Local geographic area? Or a topic?

You want to get visitors? ut in more content. Possible stuff:

• Press releases. Really. If you can get a copy of press releases for companies this gives you a lot more pages PER COMPANY witha lot more text.
• Do the old google trick. Parse google output for the company name and put it onto a page somehow mixed.

Trick is you need a lot more pages per company so that you have a chance to get a little higher volume.

Then pretty much it is game over. Point. As a company directory ou simply are not interesting. Making money / business model wont work.

Maybe you can start putting upreal content - but for saying that we need to know more.

while echoing quite a few people here that this seems a bit of an odd niche, unless you are adding lot's more value added services.

One thought looking at your site is use Google a lot more, you currently hide any useful data look at Google First Click Free options for paywall sites, while not entirely designed for your instance it could work well, combine this with your address and contact details in rdfa and or microformats and allowing individual businesses to generate more full profiles ability to add pictures or pull from a flickr stream etc. Basically turning each page into unique content for them. If you can work out the incentive from the business side to do this (your profile is x percent complete add y to complete it style might be one way) by using First Click Free you can keep your free paywall (though I would query why you want one, surely if it's free and the people looking are after the businesses info not to create their own profile) but in part make use of Google.