Testing Gmail Open and Click Through Rates

Image courtesy of digitalart / FreeDigitalPhotos.net

Email is a great tool to use in traffic acquisition; it's a way to get existing customers to come back, as well as providing a way to communicate with your market.

However, to make sure that your effort is being rewarded, you do need to make sure that you are measuring its effectiveness.

There are two key measures for this:

• Open rates
• CTR

Of course, you'll want to add conversion to this, as well, but since that requires tracking more than just the email, it's outside the scope of this article.

How to Measure Open Rates

The classic way to measure open rates is to track the number of times an image included in the mail is downloaded from your server. To try this out, create an image and upload it to a specific folder, and give it a specific name.

Then, send yourself an email, with the image linked to (i.e. not sent with the email, but provided as part of an HTML message), and open it in your email client.

What you should see is that the image is downloaded from the web site, and subsequently, since you know how many emails you sent (1) and how many times the image was viewed (1), the open rate is 100%.

On the other hand, if you send the email to someone and they delete it without opening it, then the open rate will begin to fall.

What is it testing? Your subject line. If it's not compelling, the email won't be opened.

Of course, this also only works for HTML email. If the receiver only ever reads plain text, then it isn't going to work; which is where the CTR comes in.

How to Measure Click Through Rates

The CTR, or Click Through Rate, measures how compelling the email was that someone actually bothered to click on a link to follow through to the web site being advertised or offer being made.

The simplest way to measure it is to use a bitmark (from Bitly.com, or a Goo.gl link) and simply track the number of clicks.

Of course, there's going to be a confusion for people with text only email clients, who will likely see the "Can't read this email, click here" text and then use that to show the original email. So, it's important to have two pages set up on the web server:

• the original email
• the offer itself

The first page should, of course, link to the offer page. While the results might be a bit skewed, it's better than nothing.

Gmail Changes Complicate Matters

Now, Gmail has introduced image caching for email. This means that although email users will be able to see images in their email faster, and without specifically asking for them, it's going to play havoc for measuring traffic acquisition through email.

For a start, the open rates are going to be so unreliable that you should disregard gmail recipients from the open rate calculations.

Then, you will need to pay a lot more attention to the CTR and display rates, probably by adding counters on the two pages mentioned above, and adding them specifically to custom Experiments and Goals in Analytics.

It's not the disaster that many seem to be suggesting, but it does make testing and tracking traffic acquisition through email marketing a little more complex for list managers with a large number of gmail recipients.