If you want to really target your audience, the best way to do this is to Pay For Traffic. Several major search engines offer this service and it really is the best way to pick the kind of traffic that you want, specifically seeking your type products, services or info.
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Overture: Their success has spurred the Search Engine Industry, Google adwords, Looksmart and even Yahoo now let you pay for position. Also, our most popular selling site, due to the millions of small-mid size businesses that get buried deep in the major SE's there's plenty of money to be made right now.

Listing your site within Overture's search results is the most cost-effective way to reach lots of targeted customers. You select the search terms that are relevant to your site, and choose how much to pay when customers click on your listings*. The higher you bid, the higher your site appears in our search results.

List your site now and Overture will give you:
Traffic - We deliver hundreds of millions of searches every month.

Reach - Overture search results reach 75% of all Internet users.

Targeting - Directly connect with specific audiences through custom titles and descriptions.

Cost effectiveness - Pay when targeted customers click through to your site.

Control - Choose how much to pay for each visitor.*

Easy account management - Get 24 hours a day, 7 days a week account access with the DirecTraffic Center®.

* Each account has a $20 minimum monthly spend. There is a minimum bid requirement of $0.05 per click-through.

Take your Pay-For-Performance™ advertising to the next level with Overture Premium Listings. Premium Listings, the top three results for any keyword, give you what no one else can - exposure to 75% of all Internet users by listing you on leading Web sites, such as Yahoo!, America Online, Lycos, AltaVista and many others!
Reach: Expand your reach to 75% of all Internet's users compared to the 40% reach of our Classic Listings (positions 4-240).

Exposure: Put your listings on the highest quality, most-frequently visited sites on the Web.

Maximum Traffic: Receive an average of twice as many quality clicks per month from Premium Listings compared to our Classic Listings.

Top Position: Position yourself as the #1 search listing on great sites across the Web.

Convenience: List your site once and manage just one account to be seen on the Web's most popular sites. ________________________________________________________________________

Google

Benefits of advertising with Google include:
Unique text-based ads displayed on search results that are highly visible.

Keyword targeting that eliminates waste and increases relevance.

Ads on Google's image-free pages have yielded clickthrough rates 5 times higher than industry standards.

Google AdWords is a simple and quick way to purchase highly-targeted advertising, regardless of your budget.
Purchasing an AdWord on Google is as easy as:

Your AdWords text ads appear on search result pages for the keywords you buy, and can be targeted by language and country. So, to reach collectors of tin toys you might buy the keywords "toy collector," "tin toys," etc.

Pricing for AdWords is based on the position in which they're shown. Google positions your ad based on how many users click on it over time. Current rates are $15, $12, $10 (per thousand ads shown) for positions 1, 2, and 3 respectively, and $8 per thousand for positions 4 and beyond. Accounts are opened with a credit card and no minimum deposit is required.
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Other PPC's

FindWhat.com
http://www.findwhat.com/

FindWhat is an important paid placement service because the company distributes its results on the Excite search engine, as well as on many major metacrawlers.

Sprinks
http://sprinks.about.com/

Paid placement service that posts links to appropriate areas within the About.com network of subject sites. Listings are also available by searching at the Sprinks site itself. They are also distributed to some meta search engines.