Let’s say you have a small math tutoring business in Arlington, Virginia and you’ve been using Google AdWords for the last few months to attract new clients. You’ve acquired a few good customers from the campaign, but not enough to justify the thousands of dollars you’ve been paying Google each month.

What can you do to reduce wasteful spending and improve your conversion rate?

There are lots of options — including geo-targeting, ad copy testing, campaign restructuring, and landing page optimization. But in my experience, negative match is most overlooked technique to improve your AdWords efficiency.

Broad Match: The Good and the Bad

Before you can understand negative match, you need to know a little bit about how Google shows your ads. Let’s say you’ve added the keyword phrase math tutor to your campaign. By default Google will show your keyword on what it calls broad match. This means that your ad will appear not just when someone searches for “math tutor”; it will also show up for plurals, synonyms, and other variations of that phrase.

This is a great thing and a bad thing at the same time. It’s great because your ad can show up on highly relevant search phrases you never would have considered adding, like:

  • math tutors in falls church va
  • best tutor for math in dc
  • algebra tutor for high school students

This is especially helpful if you don’t have the expertise or time to do thorough keyword research before launching your AdWords campaign.

But broad match is dangerous because your ad can also show up on search phrases that are a poor fit for your business — like:

  • free math tutor (you’re not a charity)
  • math tutor jobs in washington dc (you’re not hiring)
  • online math help (you’re a face-to-face service, not an online product or information site)

Getting organic (free) search traffic from these keywords would be fine. But you don’t want to be paying $3 everytime someone looking for a “free online algebra class” clicks on your ad — especially when there are plenty of people looking for the exact service you offer.

Which leads us to this question: how do you keep the good parts of broad match and minimize the bad?

Negative Keywords to the Rescue

Tucked at the bottom of your Keywords tab pages is a link that says Negative keywords.

Click that link and AdWords gives you a big text box where you can enter in words that you want to prevent your ads from appearing on — anytime that word or phrase is included in a search query.

If you add “jobs” to your negative keyword list, your ads will stop appearing on “math tutor jobs in dc” and any other searches that contain the word “jobs”.

Awesome. But how do you discover the irrelevant keywords that are hurting your campaign’s performance?

How to Use the Search Terms Report

Google’s basic keyword-level reporting just shows you results for the keywords you added to your campaign. So if you have math tutor as a keyword, you’ll see something like this in your Keywords tab:

But now that you know how broad match works, you know that those 466 clicks are actually spread across “math tutor” and a number of related phrases that people are searching on. To see what all those phrases are, you need use the Search Terms Report, which you can get to by clicking the See search terms button.

Now you can scan through your list and identify your worst poor-performing search queries — phrases that are getting lots of clicks but have a high cost per conversion or a low conversion rate. Let’s say the conversion goal of your website is for someone to fill out your contact us form, and that your target cost per conversion is $20. In the example below, it’s clear which keywords are performing well and which ones are performing poorly.

Individual Words Maximize Your Negative Reach

At this point, a lot of people make the mistake of taking the entire poor-performing search phrase and adding it to their negative keyword list. And AdWords encourages this with it’s “Add as negative keyword” button at the top of the search terms list. But this is a much too narrow way to approach negatives.

The problem lies in the fairly precise way that negative matching works. If you add dc math tutor jobs to your negative list, your ads will stop appearing on searches for “dc math tutor jobs” or “washington dc math tutor jobs”; but they will still appear on “arlington math tutor jobs”, “math tutor jobs in dc”, and many other variations — all of which are just as irrelevant to your business (and could be just as costly once they get more traffic).

To knock out the maximum amount of bad traffic, you need to isolate the one or two “poisonous” words in each poor-performing search term phrase. You’re looking for words that, when present, make just about any phrase a bad fit for you. For “dc math tutor jobs”,jobs is the poisonous part. For “free math help,” it’s free. And for “online math tutorial”, it’s both online and tutorial. These are the words you want to add to your negative list, one per line.

As you’re entering your negative words, try to think of synonyms, singulars/plurals, and other variations that would be equally poisonous — and add those to your list. For jobs, you might also add job, career, careers, and work. For online, you might also add web, internet, and software.

Conversion tracking makes this exercise much easier and more accurate. But for many phrases — like “dc math tutor jobs” in the example above — you don’t need to see conversion data to know that it’s a bad fit for your site. So if you don’t have conversion tracking in place, just focus on high-traffic terms in your Search Terms Report and use common sense to identify negative keywords.

Bonus #1: Using Google’s Keyword Ideas for Negatives

Especially if your campaign is new and your data is thin, you can take advantage of Google’s keyword ideas to identify negatives. Go to one of your ad groups and click Add Keywords. To the right of the text box Google will give you suggestions for keywords it thinks are relevant. These are the words it’s likely to show your ads on for your broad match keywords — and as you can see below, they are a goldmine for negatives.

Bonus #2: Negative Exact Match

What if your Search Terms Report shows that you’re getting a lot of poor-converting traffic on the keyword tutor? You’re not buying it, but Google think’s it’s a relevant variation ofmath tutor (really Google?). You can’t add tutor to your negative list, because it will kill off most of your campaign; almost all of your keywords have “tutor” in them.

Here you need to use an advanced technique called negative exact match. Put brackets around the word – [tutor] – when you enter it into your negative list. This will prevent your ad from showing on that exact search – tutor – but will allow it to show on “math tutor” and other phrases that include the word.

Learn More

Read our case study on how Say It Visually! used AdWords to turn $243 into $70,000 in sales.

I’ll be covering other ways to optimize your AdWords campaign in future issues of our newsletter, The Keyword. Sign up here to stay in the loop.

Have other negative matching tips? Questions? Share them on the Marketade blog.