You may have already heard that Gmail is starting to cache images. Everyone seems to have their own opinion. Some are writing sensationalized headlines claiming it is the end of email marketing as we know it. Others say its much to do about nothing. So what does it really mean and how will it affect you?
We can still track opens/reads
The caching of images is taking place when the contact opens your email. Not when Gmail receives it. Gmail has to fetch the image at that time so we are able to track the open/read.
We can’t track the contact’s GEO location with opens
Since Gmail is downloading the image we can’t determine the contacts location from the open alone. We can however determine it once they interact (click a link), subscribe through forms, visit your site, etc..
It’s harder to track multiple opens/reads from the same contact (but it may not matter)
Since Gmail is caching the image they only need to fetch it once. While there is some confusion over the cache life and methods to try to get around caching, we would not track two opens if a contact opens the email multiple times within a couple minutes. Over time the cache would clear (5 minutes, hours, days?) and we would record that they opened that email again.
UPDATE: We are once again able to track multiple opens/reads without any issues now.
It doesn’t affect everything (so far)
Email clients that use IMAP (such as the Apple mail app) are not affected by this. We have only seen this with the Gmail web interface so far.
This may be a good thing…
Gmail is making it pretty clear that they care about a contacts privacy. By caching, nobody can grab referring information (IP, user agent, etc..) and you can open emails with images without being exposed. At the same time Gmail is making it fairly clear that they are OK with open receipts. So much so that displaying images will be the new default option within Gmail
(without having to click to display images)
That means we will have a much more reliable unique open rate as going forward the default setting will be to always show images without requiring your contacts to click to display images.