The prices are excellent if you have a small number of images read/processed many times over a month. If you have a large number of images touched only a few times a month, it's horrendously expensive.

For example I can thumbnail ~7M images in ~2 days on my dedicated machine (40/s) which costs me $60/mo to colocate. $60/mo gets me a paltry 20k images from Imgix (though admittedly I can process them multiple times for the same price, I don't need to).

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.

Out of curiosity, what CDN does deliver 7M for $60/mo with sourcing from your colocated server?

For me Imgix is primarily a cheap CDN with the benefit of unlimited sizes of each image depending on the device.

Disclosure, I am from imgix. If you start to exceed $500/month we can offer discounts and certainly when you are looking at millions of images then a flat rate at a lower level makes a lot more sense. 30 million unique images certainly should not be $90,000, that would be outrageous.

The $60 above doesn't include bandwidth from either my transit provider or Imgix, you can purchase a CDN separately.

Imgix is 8c/GB which is certainly competitive but by no means unique. CloudFront is only $0.005 more expensive on the higest tier and gets as low as $0.02 on the lowsest. A cheaper CDN like CDN77 starts at $0.049/GB and goes as low as $0.007/GB.

Cloudfront charges for requests and it can often be the biggest component of your bill.

CDN77 performance in terms of latency is not that great. If you are looking for a cheap CDN with good performance, buy edgecast from a reseller. The only problem with edgecast is that they charge a really high fee for SSL support for custom domains

Imgix is okay, support is terrible, and status page can stay green for 15minute when they are down (eg recent fastly issue). We stuck with them when image processing was slow due to capacity which the CEO eventually publically apologised for, but in new projects we will probably avoid them.

With support I've meant the answers I got from technical support and the timing with issues.

Yes the 15min made me angry too, as I needed to read about the Fastly fail on HN instead of the Imgix status page.

What would you use in your next project?

We used imgix on last project as a last line of defense against unoptimized images due to the timing constraints of the project. However on greenfield, we would build the image optimization into the build process (could be as simple as few imagemagick commands), and the save pipeline for CMS'ish part (content blocks, adding products etc..) and then just use a dumb CDN.

Imgix really annoyed me as they didnt bother replying about the status page fiasco, this is after we gave them a free-pass with their capacity planning which made us look like idiots recommending them (i.e images loading super slow). Not again, bad ethics.

Ah been there with the imagemagick in several companies, would never go that way again.

Wait people get annoyed at 15 minutes now? I honestly read your comment as if it was 15 hours at first and agreed but come on, 15 minutes is nothing unless you're paying for a five nines SLA.