Following Goto.com's (now known as Overture) phenomenal success with pay-per-click (PPC) advertising, more than 160 PPC startups have sprung up.

Out of these 160 PPC engines, only a few may actually have the search volume to generate a respectable number of clicks for your site.

Most PPC startups require between $10 to $25 of setup fee which can be applied to clickthroughs. They offer low minimum bids of $0.01. But with limited search volumes, they may bring you only a few clicks each day!

My recommendation is to go for established PPC engines with high search volumes that can generate higher clickthroughs. The big boys are Overture (previously known as Goto), Sprinks, and FindWhat .

Overture is the best because they serve over 2 billion search queries monthly through their partnership with major search engines such as America Online, Lycos, Altavista, Netscape, Hotbot and InfoSpace.

You can test the startup PPC engines but commit only the minimum setup fees. If they generate decent traffic, you can always top up your account. That way you minimize your risk to only $10 to $25 per PPC engine. For a list of over 160 PPC engines, see PayPerClickSearchEngines.com

How To Find Relevant Keywords?

Since you are paying for each clickthrough on your bid, it makes good sense to ensure that your keywords are relevant to your target audience.

One of my favorite tools is Overture's Search Term Suggestion

Enter a keyword and it shows the number of times the word was searched - which indicates its popularity. The more popular the keyword is, the higher are your clickthroughs. Overture also generates a list of similar keywords and their search counts in the previous month.

Overture's tool is one of the best ways for finding good keywords to bid on. Another alternative is to download Good Keywords.

Enter a keyword into this free software and it will display a list of relevant search terms and their search counts across multiple PPC engines.

You can also try JimTools' Keyword Toolkit.

JimTools can generate a list of related keyword possibilities, some with search counts, from Goto, Google, Magellan and WebCrawler.

How Much Do I Bid?

The bigger PPC engines such as Goto and Sprinks require a minimum bid of $0.05. Startup engines have lesser minimums of $0.01.

How much to bid depends on your return-on-investment (ROI) calculations.

For example: If you bid $1.00 per visitor, and 1 in every 10 visitors buys your product, your cost-per-sale is $10.00.

So, if each sale of your product produces a gross profit of $15, then your net profit will be $5.00 ($15 gross profit minus $10 cost-per-sale).

Your return-on-investment (ROI), before non-marketing expenses, is 50.0% ($5.00 net profit / $10 cost-per-sale). Always price your bids to achieve a positive ROI!

A great tool that you can use to compare bids for a specific keyword across multiple PPC engines is at CompareYourClicks.com

To read about how you can maximize your returns from PPC engines, go to InternetMarketingFocus.com

You'll learn how to reduce your bids while still maintaining the same ranking or get a top 3 position for maybe just 1 cent more!

How Do I Track Clicks?

Most of the time, you'll notice that the number of clicks tracked by yourself is between 15% to 30% more than the clicks the PPC engine reports.

This is because reputable PPC engines such as Overture have installed anti-cheating mechanisms that prevent your competitors from repeatedly clicking on your listings and wasting your bid fees!

They will count multiple clicks within a specified timeframe from the same computer as only one clickthrough while your own log will usually register the multiple clicks.

There was once when I noticed that my log was registering less clicks than Overture's reports. They were experiencing some bug which prevented clicks from being properly delivered to the advertiser's website.

Because I was tracking my clicks, I notified them of the problem and they credited my account for the bad clicks. Tracking your clicks give you a more reliable picture of how well your PPC campaign is performing.

If you have access to your CGI directory, I recommend LnkinLite, a small yet powerful tracking software that can track clicks to your site in the background.