In a recent teleconference, I was asked several questions about specific problems people were having converting clicks to customers.

In the first article of this series, we defined conversion, including what you should look for and what factors have the biggest impact on conversion rates. The second article covered measurement, including measurement tools, the differences between log- and browser-based measurement, average conversion rates and why it helps to track how people use your Web site.

In this final part of this series, we'll be looking at where traffic arrives from and how that affects conversion, specific search engine queries, PPC issues and other general topics.

How do keywords affect your conversion rate in terms of search engine optimization (SEO) or search engine marketing (SEM)?

Keywords are important for two reasons.

First, by using the keywords that relate to your reader you will be listed by search engines—which means that people can find you. Notice that I phrased the last sentence carefully. I said, "keywords that relate to your reader." It's important to understand that what you consider keywords might not be the keywords your visitors are using to reach you.

Second, and more important, keywords help to qualify your audience after they have arrived at your Web site. If you click through from a search engine to a Web site and the headline or first paragraph does not strike you as relevant to what you're looking for, you're likely to "bounce" (leave the site). The keywords that you use help to assure your visitors that they are in the right place.

Good use of keywords embedded in your copy and content will help you to attract the right kind of people. Second, they will help to effectively qualify them as being in the right place. If you manage to both attract and qualify, the readers are then more likely to click through to find out more about what your Web site is about. If they do that, there is a much higher chance that they will convert to your desired goal.

A good SEO or SEM company is one that understands that it's about answering the visitors' needs, not simply packing the Web site with related key words and phrases.

What Is pay-per-click (PPC)? Is it worth the money? Does PPC affect conversion?

PPC is when you set up an account with a search engine (Google or Overture, for instance) and run ads that appear when a visitor to the search engine requests a certain keyword. If a visitor clicks on your ad, you pay a predefined fee to the search engine. Done correctly, PPC is a good way to drive people interested in your product or services to your Web site. Well-executed PPC marketing should positively affect conversion.

One of our clients recently asked about a PPC campaign (run by another company) that was converting poorly. The reason was that the ad was optimized to be clicked-through, but not optimized to qualify the reader. The product in the ad was a mobility scooter priced at $1,850. The ad explained that you could get great discounts on mobility scooters, and therefore the click-through on the ad was high. So it was an expensive campaign for our client. But it didn't convert into sales.

Why? The ad should have tried to qualify the reader more by including the price and location in the ad. A fair percentage of visitors who are interested in purchasing an expensive item like a mobility scooter will want to see it first. Therefore, a good way to actually sell this product is to tell the reader the price and location so that they know without going to the Web site whether the product is for them.

Furthermore, mentioning price in the ad prequalifies that they have the money. So if they have the money, are in the market and are in the same city—there is a much higher chance of a purchase.

Another thing to remember in PPC campaigns is the relevance of the ad to your landing page. It's a frequently overlooked problem. Often, the PPC ad doesn't relate directly to the landing page. Our client did this correctly by linking the Google ads directly to the page about mobility scooters. But it's a common mistaketo link the ads to a home page—an approach that expects the visitor to do the work of finding the item.

Too many PPC companies work on click-through as their gauge of success. They see it as their job to drive the traffic rather than convert it. The idea of successful PPC marketing is simple economics. You spend less than what you earn from the visitors' arrival, and so you make a profit.

However, ads that use the shotgun approach aren't doing you any favors. Ads that you're paying for should bring in very interested and pre-qualified visitors who convert at a higher level.

When visitors arrive at our Web site, they are a mixed crowd with different expectations. How do we cater to them all?

You can't please everyone, and it's fatal to try. You have to figure out your best chance of business and cater to the appropriate clientele. If you have a large, varied audience or are running some kind of portal, then you should have a clear strategy to attract people to dedicated sections of your Web site.

For instance, small businesses have thousands of individual, varying wants, needs and requirements. Your landing page (home or index page) is going to have a very hard time catering to all of those small-business customers effectively.