Google now gets more than 60 percent of U.S. search queries, and Yahoo gets about 20 percent; thus, the majority of searches originate on major engines. The top three (Google, Yahoo and Microsoft) are called first-tier engines because they deliver high traffic levels, good conversion rates and the best reporting tools.

Second-tier engines include the smaller niche, vertical and local search engines and directories that are not so well known or popular. These engines typically have less traffic than the majors but offer less competition for keywords and cheaper keyword prices. While second-tiers may get less traffic, even 1 percent of search market share can equal $100 million in revenue.

There are a number of pros and cons to advertising on second-tier search engines. Selecting the right second-tier for your search campaign is key to success, so it's important to investigate every angle, including the engine's user base and income level, reporting tools, campaign management tools and click fraud protection policy. Possible candidates should be tested for ROI before committing large sums of money.

Advantages of second-tier engines
The top benefits of second-tier search engines are as follows:

• Lower per-click costs
• Less competition for competitive keywords
• Highly targeted audiences
• Quick and easy ad copy testing
• High touch customer support
• Additional source of traffic and conversions

While the main advantage is cost, you can also get some great contextual and behavioral offerings for a fraction of what you might pay on first-tier engines. For example, if your target audience is NASCAR fans, you might try advertising on Kanoodle, where your ads appear on a network of search engines and other popular sites like CNET's Search.com and the InfoSpace properties, including Mamma, WebCrawler and Dogpile.

It is important to define your campaign objectives clearly on second-tiers, setting budget restrictions and a timeframe for determining campaign success.

Most second-tiers give you the option of pausing a campaign to take advantage of working hours or click volumes, which can be advantageous for smaller businesses. You can log into your PPC account in the morning, check the previous day's activities, turn on the accounts when you expect the bulk of inquiries and then pause the account when volumes taper off.

Disadvantages of second-tier engines
The top disadvantages of second-tier search engines are:

• Less traffic volume
• Lower conversion rates
• Lower traffic quality
• Higher click fraud potential
• Less powerful reporting tools
• Aggressive sales reps

The most frequent complaints are low traffic volume, low conversions and low-quality traffic. However, you can compensate for reduced traffic volume with a lower cost-per-conversion if traffic converts well, which happens when you test and select your best performers.

While a major concern on second-tiers has been click fraud, many now provide click fraud protection. For example, ABCSearch, 7Search, eZanga and many others offer anti-fraud technology with AdWatcher and Traffic Advisors.

Note that the disadvantages above do not apply to all second-tiers. Some provide robust reporting applications (e.g., Miva), while others provide great traffic and conversions (e.g., Business.com).

It is important to know what a second-tier's unique selling points are, and the best way to find out is to ask a sales rep. Stay away if they don't provide this information.