The challenge for email marketers, especially ones that are looking to push the envelope is that technology changes all the time, and what is often a ‘hack’ that allows you to do truly innovative things with the channel for email marketing will no longer be supported, and often times this is with little or no notice. In fact it is often only when you start recognising issues that the change comes to light.
Update (17/12/2013): Bonar Calls #BS on Gmail Myths
This past week Gmail did just that, made a fundamental change to how they serve images and this was widely reported on a variety of blogs.
What changed in a nutshell is that images in an email are served via a Gmail Proxy, if Gmail recognises it is serving an image it will also cache this resource. This is to improve the loading time and the overall experience of its users. The problem? ESPs using an image to track whether, when and how often an email is opened by recipients. Now you are no longer able to track how many times a recipient opened, if Gmail recognises that you are serving an image. You will only have the opportunity to see the first open by any recipient using the native web based Gmail interface.
Further we are no longer able to see the IP address of the recipient nor the user agent (what device they used to collect their email) as this is all passed via the Gmail Proxy and the information is stripped prior to being pass to the ISP.
Whilst many have stated that they are seeing issues including leading vendors such as MailChimp, others state they have had no issue’s with the open tracking. This is important, why is it that customers of SmartFocus, Campaign Monitor, Lyris and a handful of other ESP’s are not having their open tracking affected? If SmartFocus or Campaign Monitor can do it, then in theory any platform should be able to do it.
You can view my video below if you want to see how multiple opens are tracked within one platform despite the changes. From what I can see nobody is at this time able to resolve the issue of device tracking or IP address/geolocation, however the open tracking is not proving to be an issue.
It is all a matter of a small change in how the tracking pixel technology is implemented at the ESP. I had no intention of revealing this tiny bit of secret sauce (it would not be hard for competing ESPs to put in a little effort and work it out for themselves, I had already pointed them in the right direction) but one individual went out of their way, investigated and published their findings. I take my hat off to René Kulka who wrote this fantastic post on the subject: Gmail’s image caching: How it affects email marketing & how to heal your opens tracking
EDIT: Rene has done further testing and has found the crucial element is “ ‘Content-length’ (=0) than of ‘content-type’. Returning nothing in combination with a HTTP 200 OK forces Gmail to grab the tracking code over and over again.”
As stated by René ”the crucial difference is that … CampaignMonitor server does – at first glance – not return an image. Gmail ignores it, and every call hits the CampaignMonitor server so that every open is counted. Ergo: If you want to measure your total opens, don’t let your tracking URL return a resource of type ‘image’.” The secret is all in the HTTP header information as is illustrated in the post by René.
That really is all there is to it, now there is nothing to say Gmail will not change things again in future. However if your ESP or EDM platform is telling you it no longer is able to report multiple opens for Gmail recipients. Point them in this direction, and let them know there appears to be a relatively simple fix.
They will still use image tracking via a pixel, but the ‘magic’ is likely in the headers returned with those files. Whilst they are looking at that element they should also consider implementing P3P headers as defined by privacy best practice and part of the do-not-track movement.
This will not resolve the geolocation/IP or device tracking issue’s.