Skip to Main Content

May 21, 2008 | 7 minute read

PPC Copywriting: The Evolution of a PPC Split Test

written by Linda Bustos

Spoof Adwords AdYesterday we talked about persuasive copywriting for PPC ads, and as promised, today we're going to talk about strategies for split testing ads.

I've heard most PPC experts recommend you test headlines first, because they are most visible and are believed to influence click through rate more than body copy (because people have a tendency not to read things if they don't have to). But I'm going to go against the gurus and suggest how you could test offers and value propositions first, using a hypothetical campaign for "wireless headphones."

The Strategy

This approach uses Dynamic Keyword Insertion in headlines for your first few rounds of testing. You have more room to market yourself in ad copy than in the headline. You can test offers, calls to action, value propositions -- copy that answers the question "why should I buy from your site?"

Dynamic Keyword Insertion means Google will match your headline to the searcher's query. If Jimmy searches for "wireless head phones" or "cordless headphones" the ad would adjust itself accordingly for maximum relevance so long as that keyword is in your Ad Group and fits in the headline. If Jimmy searches "I'm looking for killer wireless headphones" (a long tail term), as long as "wireless headphones" is broad or phrase matched, a default keyword would display as the headline. In this case, simply "wireless headphones." You'll see an example of how to use this feature in the first screenshot, or read more in Google's DKI tutorial.

But we're not going to use keyword insertion in the ad text - there's no need to keyword stuff. We want as much space for testing compelling offers, not redundant keywords. It's not SEO, it's not the year 2001 and we speak English here. Here's an example of totally useless keyword repetition (real ad):

Keyword Stuffed PPC Ad

Alright, let's get started with a hypothetical example of 5 rounds of PPC ad testing:

Round 1

First you're going to pick 2-4 versions of an ad to run evenly against each other.

Headline: Use DKI for your headline

Ad Copy Line 2: Make sure you have your best unique value proposition included in the ad. I recommend using it as your second line, and using the top line as your testing line. A unique value proposition is the most compelling strength or offer you as a retailer have that sets you apart. If you offer free shipping, free returns, flat-rate shipping, no hassle returns, money back guarantees, have won awards, or anything else that builds trust or adds value - use it!

Ad Copy Line 1: Here's where you microtest your ad. Many tests have found including numbers - whether a price, percentage or otherwise makes your ad stand out and improves click through. If you offer low prices, it may make your ad more attractive than others. If you want to deter bargain shoppers, a higher price can save you money on clicks and improve your conversion rate. You could here test price vs. non-price, but for this example, we're going to test variations of showing a price.

Display URL: Some advertisers use dynamic keyword insertion at the end of the display URL (so long as it fits) to boost the keyword relevance, and it may or may not improve click through. An argument could be made that shorter URLs have higher click through. Also, www and non-www URLs may be tested. You really need to test this yourself, but not in round one. If you have too many variables in your testing, you won't know whether it's the ad text or the display URL that's performing better.

In round one, we're going to use www URLs for every ad variation, with capitalization, as there has been many studies that do suggest this gets higher click through. Since I want to play it safe here, we're going to always use capitalization in every round.

Okay, here are the ads we're starting off with - but there's an error, can you spot it?

Round 1 Testing

Answer: We're testing pricing offers, so we want all else to be identical. We can test "name brands" in a later round.

Don't forget to edit your campaign settings and select "show ads more evenly" so you can properly split-test.

Now we get to make up some results. Let's say that "$29.99 and Up" had low click through rate of 0.41%, but the other two versions had 3.0% and 3.72%. And let's assume a quick check with's confidence tool declared "From $29.99" the statistical winner. Before you decide it's a winner, make sure that it also has a good conversion rate - that these clicks end up buying. You don't want to pick an ad only costs you money and doesn't make you any.

If you have an ad that rocks click through rate AND conversion rate, you can move on to round 2.

Round 2

Pause the ads that didn't "win," and let's ad new ads to test. If you delete your ads, you'll never be able to see their history again.

Now I want to know the impact of URL versions as follows:

Round 2 Testing

I'm going to pretend that the non-www, non-trailing keyword version performed best. On to round 3...

Round 3

I'm trying out more creative copy in the first line. I want to know what seems to be most compelling about wireless headphones. Is it range and clarity of sound? Is it better bass? Is it cool styles? Are name brands important?

Round 3 Testing

OK, again, totally arbitrary - let's assume the test resulted in "Stylish, Wicked Bass" as the winning creative. Can this be further tweaked?

Round 4

Round 4 Testing

At this point (or in any round), there might not be a clear winner. You might want to keep testing different micro-variations until you get a definite star ad before you move onto the next round - testing headlines. Or, you might decide that they're all performing decent and you can choose one you like best and move on to the next stage.

Round 5

Now I'm ready to test headlines. There are common modifiers PPC advertisers will use in headlines - the ones I've seen most are:

  • unique
  • discount
  • cool
  • cheap
  • find
  • buy
  • compare
  • on sale
  • sale
  • save on
  • for less
  • get
  • need [keyword]?
  • reviews
  • [brand] [keyword]
  • [keyword] [country]

You might want to try these, but remember that once you add the bargain hunter modifiers, you could attract clicks you don't want (that's why including price, even if higher than competitors helps). But definitely avoid testing different brand names. Unless they are doing specific branded search, you don't want to use brand names in your headline. It makes your selection seem too restricted like you only offer one brand (less selection) or you have made a decision for them. Unless the searcher is familiar with the brand, it's not effective. Your branded products should have their own Ad Groups, anyway.

If you've had a clear winning ad copy in previous rounds, you might want to inject these words into your headline, or try your unique value proposition in the headline, like "$0 Shipping" to stand out. Just make sure you're not wasting ad copy by repeating your offer again in the lines of text. And use your dynamic keyword insertion headline as the "control" version - you want to see if headline variations outperform it.

Here's an example test, can you spot the error?

Round 5 Testing

If you noticed that one of the ads does not have "wireless headphones" in the ad text or headline, you're correct. You don't want to sacrifice keyword relevance for catchy headlines. Double check your ad text, it's easy to forget the details.


Again, there are many ways you can approach your testing, this is just an example of how you could go about it. This strategy involves testing micro-changes. You can also test really different copy against each other. Tomorrow we're going to show you how to reduce your risk when doing such tests.

Until tomorrow, here are the key points:

1. Keep testing. You can always "beat the control" - so long as you keep trying.
2. Don't test more than one variable at a time.
3. Use your unique value propositions whenever you can.
4. Use prices when it makes sense, or other numbers.
5. Use to check if your test has produced a winner or not.
6. Don't make your decision based on click through rate alone. Make sure the ad converts.
7. Capitalize The First Letters of Your Words And URLs, It Is A Proven Strategy.
8. Avoid using brand names in headlines unless your ad group and landing page are targeted to only that brand.
9. Triple check your work for spelling and other errors. Make sure your landing pages are tied up correctly.
10. Keep reading Get Elastic for more tips for online marketing. Subscribe if you haven't already!