Google AdWords provides advertisers with four distinct types of keyword matching options to help you deliver your ads to searchers: broad, phrase, exact and negative. There are plenty of resources around that describe what each of these options are under the hood, and I imagine that many AdWords advertisers refer to Google's Learning Center page on the topic: Keyword Matching Options.

Now, some of you might have heard that Google now has the most powerful brand on the planet. Branding is rooted in eliciting trust, and so this news tells us that the majority of Internet users out there trust Google. When it comes to keyword matching options though, I advise you to be just a little suspicious of Google. Here's why…

The default keyword matching option in your AdWords account is broad match. Broad matching will definitely help you get the most impressions for your ads, but unless all you are after is clicks and traffic, broad matching is going to empty your pockets and leave you as one unhappy marketer. Broad matching is just too general to be of use on it's own. Negative keywords certainly help you more finely tune your broad matches, but in my experience it's simply not enough to filter out the large number of clicks from irrelevant searches. I've tested a handful of broad match terms accompanied by hundreds of negatives and still had this combination perform quite poorly when compared alongside exact matching. Google doesn't give you any warnings about the potential pitfalls of using broad matching though, and why should they? Google banks more cash when marketers use broad matching. Why would they share that helpful tidbit with us when it could potentially reduce their earnings?

My advice to new PPC advertisers is to only use exact matching–at first. I have generated excellent results using exact matching alone, with both CTR and conversions. When you're ready to open the gates a little more, do a test with one of your ad groups, adding one or two phrase matched keywords along with a very long list of negative keywords to filter out the undesirables. Using this cautious method, you'll quickly find out which keyword matching options will work best for your campaign. I recommend that broad matching be used only with very careful and regular testing.

Do read the materials in Google's Learning Center–it's an excellent and free resource–but also be aware that some of the content might be self-serving. Balance that out by regularly checking in with PPC blogs and forums, where you'll find that AdWords users are generally more than willing to share their tips and secrets for improving AdWords performance.