We're talking about a situation where all images are fetched immediately on delivery regardless of the email being opened.
In that situation it does not "provide open tracking" any more. You send 100,000 emails with 100,000 slightly different URLs, then you get 100,000 images fetched. You get zero information about if the emails were opened or not.
So at that point, you stop putting tracking information in the image URLs, as it's no longer giving you any information, and just means you have to serve the same image 100,000 times instead of just once.
Now Google only has to do 1 HTTP request and store 1 image. It doesn't have to do 100,000 HTTP requests, and store 100,000 images in its cache.
Email inbox providers would have to incur 100% of the cost in a very coordinated way, and then hope that doing so bullies the senders into turning off their open tracking. It’s not going to happen.
Major inbox providers like open tracking because it is a tool for senders to improve their products and clean their lists, which ultimately reduces email volume and makes email recipients happier.
The people at big senders and big recipients talk to each other. If there is going to be a change around open tracking, it will probably be along the lines of a negotiated feedback loop like they have set up for spam complaints. Possibly with the inboxes charging the senders for the privilege of getting that feedback.
> Email inbox providers would have to incur 100% of the cost in a very coordinated way
Yes, and in the long term, providers like google for example, will probably end up saving a tonne of money by not having to proxy all these tracking resources.
> and then hope that doing so bullies the senders into turning off their open tracking. It’s not going to happen.
It's got nothing to do with bullying. Their "open tracking" would immediately become useless. The sender can leave it turned on, collecting no information, and using their bandwidth. Or they can turn it off, as they should never have been doing it in the first place.
> Major inbox providers like open tracking because
I don't care what mail inbox providers like. We shouldn't be taking that into consideration. Perhaps the postoffice would like it if people who put letters through my letterbox knew how much time I spent reading those letters. I don't care. They're not owed that information. Luckily they haven't found a way to abuse the postal mail system in the same way that email senders have.
I don't know how we get the big email providers to get rid of this plague of open tracking. Perhaps they will take it upon themselves at some point, due to pressure from their users, who want privacy. Gmail's already most of the way there now they've set up their proxying system.
In that situation it does not "provide open tracking" any more. You send 100,000 emails with 100,000 slightly different URLs, then you get 100,000 images fetched. You get zero information about if the emails were opened or not.
So at that point, you stop putting tracking information in the image URLs, as it's no longer giving you any information, and just means you have to serve the same image 100,000 times instead of just once.
Now Google only has to do 1 HTTP request and store 1 image. It doesn't have to do 100,000 HTTP requests, and store 100,000 images in its cache.