[andrewingram]

Right. In my last two jobs, one of them had a relatively low volume of images (let's say, around 30k being requested per month) scaled to an arbitrary number of transformations, whilst the other had a high volume of images (millions) with a low number of transformations.

In both cases, the cost of doing it ourselves (using something like thumbor) would have been a few thousand per month. In the former example, imgix cost a few hundred, in the latter it would have cost in the hundreds of thousands.

imgix is the fastest of the services i've looked at (transformation time is roughly half what I got from cloudinary, and average response time is also about half), but its pricing model means it's completely unaffordable for certain types of product.