Pay per click:

PPC Program search engines guarantee top listings for selected keywords. These keywords or search phrases are the ones relevant to the client's business and are bid upon by the client and his competitors. The highest cost of pay-per-click for a key phrase gets the top-most placement and consequently the greatest and most targeted traffic. Bidding for keywords in Overture and Google is another method of capturing the right kind of traffic - the customers who are looking specifically for your product or service. We offer a Paid Pay Per Click Search Engine Keyword Management Services to increase the Website Traffic.

MORE On PPC:
Pay Per Click (PPC) Search Engines
Pay Per Click search engines and advertising provides web site owners the opportunity to buy their way to better positions on search results pages. Learn about PPC, the costs, and if it is a viable option for your site.
  
What Is Pay Per Click?
Pay Per Click advertising on search engines allows you choose keywords you would like your site to appear for when a search is performed. You decide how much you are willing to pay each time a person clicks on the search results. The more you are willing to pay, the higher your site will appear in the results for the keywords you choose.
  
Which Search Engines Allow Pay Per Click Advertising?
There are hundreds of PPC search engines.
 
The largest companies in the pay per click industry are Overture and Google. Google is not a PPC program  search engine, but it does provide paid advertising in text ad boxes to the right of search results it delivers. Pay per click affiliate program gives better results.
 
The pay per click search engines listed in the box in the right column of this page are not as large as Overture and Google, but they are worth a look. As mentioned above, one advantage these search engines can provide is they generally have lower costs per click to rank for a keyword than the larger search engines.

In addition to these, you may also be able to find thematic search engines that serve your industry or specifically cater to your target audience.

Important Considerations
A very important point to keep in mind with pay per click is you must test, test, and test some more. Don't start off with a major investment. Start with the minimum and see how the search engine performs in terms of the traffic it delivers and how well that traffic converts into paying customers.
 
An essential part of your testing is having a method in place that allows you to track your return on money invested.

For example, if your goal is to bring in new subscribers to your newsletter, you could direct visitors arriving from your PPC link to a subscription form set up just for them. You can then monitor how many clicks actually result in a new subscription. As such, you will know how much you are paying for each new subscriber.
 

Before spending any money with a PPC search engine, be sure they can answer the following questions:
How many searches a month are performed at the search engine?
What major search partners or affiliates does the search engine have?
How many searches are generated each month by the search partners or affiliates?
Is it possible to opt out of having your listing appear in the results of the affiliate sites?
What fraud prevention mechanisms are in place?
What is the procedure for filing a "fraudulent clicks" report?
How many searches a month are performed at the search engine?
What major search partners or affiliates does the search engine have?
Will an account be credited for fraudulent clicks discovered?
Is it possible to opt out of having a listing appear for searches originating from specific countries?
Is there a posted terms of service for search partners or affiliates. Look for search engines that have very strict guidelines for dealing with their search affiliates. This is important because you want to be sure the search engine is working hard to prevent fraud among its affiliates.?