Of all the Website promotion tools available, Pay per Click is one of the most often used and most effective.

Overture.com (formerly Goto.com), recently acquired by Yahoo! and now renamed Yahoo! Search Marketing Solutions, is a so called Pay per Click (PPC) Search Engine. Searchers perform queries in the same way as they would when using the major (non-PPC) and Overture then returns a number of results in the form of listings submitted by their advertisers. The listings are the so called sponsored listings. If the search term returns a s small number of sponsored listings, the results are supplemented by so called additional listings which are supplied by Yahoo!

The listings are ordered by two criteria. Firstly, Overture's advertiser guidelines ensure that searches only return listings that are highly relevant to the search query. Within that set of relevant results, listings are ranked according to how much the advertisers bid at the time of the search. The higher the bid, the higher the rank and the higher the amount of traffic. When a searchers clicks on a listing, the advertiser's account is debited by the bid, also known as the Cost per Click or CPC. There are no other costs to the advertiser, who only pays for clicks received.

And therein lies the attraction to most advertisers: there is no optimisation process, no linking required, no time lost in getting ranked in the major Search Engines. Provided you adhere closely to Overture's advertiser guidelines on composing listings (a title and a short description) even a totally new advertiser can have their listing online in about 5 business days. Bringing on additional listings for existing accounts usually takes no more than 24 hours.

Geo targeting is also possible by advertising in Overture's country specific versions, but to target more than one region you'll have to set up country specific accounts.

Overture offers a good set of tools and tutorials for the beginner, including a search term suggestion tool for finding relevant and related search terms and how much they've been searched for in the recent past.

Reporting on bids, clicks and other metrics is excellent and will help advertisers strongly in maximising ROI. Overture recently introduced conversion tracking which allows advertisers to count the number of clickthroughs that actually take action (make a purchase or complete a form).

Since its acquisition by Yahoo!, Overture has started to offer an alternative to its own PPC engine. SiteMatch uses PPC to show results in Yahoo's main search results. We wouldn't recommend SiteMatch at the time of writing. It does require a small annual fee per listing, a small deposit to fund the clicks and it uses a flat CPC, which cannot be altered. Furthermore, advertisers have no say in where the site will appear: it remains entirely Yahoo's discretion where (search terms) and in what position (ranking) , so advertisers are left with very little control.

Despite the Sitematch's drawbacks, conventional PPC as supplied by Overture, FindWhat and many others would seem like a great way of generating targeted traffic to anyone's budget and so it is. But there are inherent drawbacks to PPC in general.

Firstly, PPC is in essence a listing auction, with the highest position (and the most traffic) going to the highest bidder. That inevitably leads to "bidding wars", with advertisers aggressively trying to outbid each other to maintain their relative positions. With more and more advertisers coming online, the cost of PPC advertising has steadily increased for this reason. A few years ago Overture increased their minimum bid from 5 c to 10 c, a whopping 100% price increase!

To optimise their often very large campaigns (often comprising hundreds of listings and corresponding bids) advertisers use Keyword Bid Optimising software to ensure they maintain good rankings, without having their ROI eaten away by runaway cost per click costs. A Keyword Bid Optimiser is essential if PPC is going to be an important website promotion tool for you (see Toolbox, left).

Secondly, compared to the major Search Engines, most PPCs are dwarfs. Apart from Google AdWords, the two largest PPCs combined , Overture and FindWhat, serve less than an estimated 10% of the total worldwide search volume. That doesn't mean you won't get traffic: it simply means that there is a glass ceiling to how much you'll get, no matter what you do or are willing to pay.

Thirdly, the most often cited complaint about PPC advertising is that conversion rates (number of sales divided by number of clicks, usually expressed as a percentage) is lower compared to "natural" Search Engine traffic. This is probably caused by the fact that searchers realise that PPC listings are in effect advertisements and therefore maintain a healthy dose of scepticism when clicking through to the sites.

There are of course many more PPC Search Engines, other than Overture and FindWhat. Many are small and offer great incentives to start using them, in particular by offering bonuses for signing up. These fledgling PPCs are excellent tools for anyone wanting to test the water without spending much or even anything at all. They are most suitable to test high volume search terms, on which even small Search Engines still receive traffic. Check out the Toolbox, left, for a great book on Overture, FindWhat and so called free PPC SEs.