How the distribution of clicks by device can look like a conversion rate problem.

Paying for clicks but not getting conversions hurts!

We PPC people dream about the conversions graph going up up up to the right but performance drops for no apparant reason.

I used to dread trying to figure out why a good campaign went bad. Then I learned the five whys technique. It’s given me the confidence to know that I’ll always be able to figure out the real reason (or reasons) why conversions dropped.

The five why’s technique is a procedure used to get to the root cause of a problem by asking the question “why”. Each answer forms the basis of the next question. The five in the name comes from the suggested number of iterations needed to get to the heart of the matter.

Toyota Motor Corporation developed the technique to root out manufacturing problems. It's perfect for diagnosing a drop in conversions.

Here’s an example of how it works from Wikipedia.

My car won’t start. (The problem)

1. Why? - The battery is dead. (First why)


2. Why? - The alternator is not functioning. (Second why)


3. Why? - The alternator belt has broken. (Third why)


4. Why? - The alternator belt was well beyond its useful service life and not replaced. (Fourth why)


5. Why? - The vehicle was not maintained according to the recommended service schedule. (Fifth why, a root cause)


You have to get to the real cause of the problem or you (try) fix the wrong thing. In this case charging the battery wouldn’t fix the problem because it’d go flat again in a couple of days.

The catch is that you can't use the technique on the total number of clicks and conversions. You have to look at the distribution of those clicks.

The distribution of clicks changes across all aspects of your campaign. A keyword that contributed 10% of the total clicks this month might have contributed only 6% of the clicks the month before. Same with the ads, locations, demographics, and every other aspect of your campaign.

The distribution can make a huge difference to the conversion rate. I've written about examining changes in distribution for keywords here. This article looks at how the distribution of clicks across devices - mobile, tablet and desktop - might be the culprit for fewer conversions.

Let’s look at some numbers. (I’ve shared this example previously in case it looks familiar)

Say your conversion rate dropped from 13% in May to 6% in June. That's a big enough drop to get anyone worried.

At first glance this looks like a conversion rate problem. But, if we segment the clicks by device, a different picture emerges.

Desktop performance

Mobile performance

We don’t have a conversion rate problem:

• Desktop clicks are converting at the same rate (15%).
• Mobile clicks are converting at the same rate (5%).

What we have is a change in the mix between mobile and desktop clicks.

• In May we got 650 desktop clicks. That dropped to 100 in June clicks.
• We got 150 mobile clicks in May and that went up to 700 in June.

The answer to the lower conversion rate lies in using the 5 whys technique to get to the root cause of:

• Why we got fewer desktop clicks and more mobile clicks.
• Why the mobile searchers convert at a much lower rate than the desktop ones.

Related articles

Why a Google Ads account audit Isn't enough

Testing Google Ads for an RV Campground

Why negative keywords are becoming less effective in Google Ads

What’s the right bidding strategy for a brand new Google Ads account?

You can't run profitable Google Ads if your pipes are leaking

The campaign looks good but the ads aren't profitable

Topics you'll find on this site