How does HTTP compression factor into image optimization? Is it possible to optimize an image but the HTTP compressed size ends up being greater?
You should release a monthly report with this same algorithm. You should also put in a column for competitors algorithm (not the just ones you beat, all of them).
Don't forget that some images are loaded after the page and content load, so they have very little impact on user experience (and all these sites make heavy use of CDNs).
The bandwidth and mobile loading might not be an issue because of their massive amount of data-centers to serve content from.
It seems like it to would be easy to test the new image to see if anyone reports any issues, but there might just not be any benefits to reducing the homepage image by 40%. Make sure you consider that the homepage image is being scaled smaller than the actually image is, some optimizers take this into account and will give you a scaled image.
Seems their solution is both cheaper and better?
I felt a great disturbance in the Force, as if millions of developers suddenly cried out in terror...
Joking aside it is usually a win to reduce page load sizes from a speed and bandwidth point of view (which on a heavily tracked site can add significantly to costs) occasionally you have to be careful as some of the compression methods result in non-standard or "technically standard but the client doesn't really do it that way" files which can render corrupted or more slowly.