"Always be testing"
☝️ That's the creed of the modern digital marketer, right?
Well it turns out that there's a limit to how much value you'll receive from testing something into the ground.
In a world of scarce resources and limited time, I want to share a perspective on choosing what to test and how far to take it.
Landing page conversion rates are one of the most popular components to test in a digital marketing mix. There are dozens of tools dedicated to landing page A/B and multi-variate tests.
Without a doubt, increasing your landing page conversion rate can provide major lift to your campaign, particularly when it comes to lowering cost per acquisition in your paid traffic campaigns.
But are all landing page gains created equally?
🚫 Nope. Let's consider the scenario below:
For this example we'll assume that the following two metrics are constant:
Let's imagine that each round of testing and optimizations move our landing page conversion rate up in increments of 5%.
You can see that with the first improvement, a 20% to a 25% page conversion rate, the CPA (cost per acquisition) drops from $2.50 to $2.00 - a 20% reduction in cost, hoorah!
At scale (aka higher daily spend amounts), this has a monumental impact on the profitability of the campaign.
But look at the next increase: a boost from 25%-30% yields a 16% decrease in CPA. As you look down that % change column, a pattern emerges: as conversion rate improves at fixed increments, the relative improvements to CPA get worse and worse.
Look at the graph above. See how steep the red curve (CPA) is in the beginning? That represents the immediate and dramatic gains the campaign will see with first round of improvements to the landing page conversion rate.
But as the conversion rate improvements continue, the red curve flattens out. The bump from 20% to 25% brings CPA down from $2.50 to $2.00 while the bump from 65% to 70% takes CPA from $0.77 to $0.71. Womp womp. 📯
What we've stumbled upon here looks similar to a classic economic principle called, The Law of Diminishing Marginal Returns. If you study for 10 hours straight, the gains you'll see from hours 9 and 10 when you're exhausted are vastly different from hours 1 and 2 when you're fresh.
So if the majority of value in landing page testing comes from the initial gains, how should this impact our focus?
With a lot of testing and a little bit of restraint, you can should be able to get the very most out our your landing pages!