1. Switch to an external image provider.


Unless your website is an all-text affair, images will always consume the lion's share of your outgoing bandwidth. Even on this site, which is extremely minimalistic, the size of the images dwarf the size of the text. Consider my last blog post, which is fairly typical:

Size of post text ~4,900 bytes
Size of post image ~46,300 bytes
Size of site images ~4,600 bytes
The text only makes up about ten percent of the content for that post. To make a dent in our bandwidth problem, we must deal with the other ninety percent of the content-- the images-- first.

Ideally, we shouldn't have to serve up any images at all: we can outsource the hosting of our images to an external website. There are a number of free or nearly-free image sharing sites on the net which make this a viable strategy:


Imageshack
ImageShack offers free, unlimited storage, but has a 100 MB per hour bandwidth limit for each image. This sounds like a lot, but do the math: that's 1.66 MB per minute, or about 28 KB per second. And the larger your image is, the faster you'll burn through that meager allotment. But it's incredibly easy to use-- you don't even have to sign up-- and according to their common questions page, anything goes as long as it's not illegal.

Flickr
Flickr offers a free basic account with limited upload bandwidth and limited storage. Download bandwidth is unlimited. Upgrading to a paid Pro account for $25/year removes all upload and storage restrictions. However, Flickr's terms of use warn that "professional or corporate uses of Flickr are prohibited", and all external images require a link back to Flickr.

Photobucket
Photobucket's free account has a storage limit and a download bandwidth limit of 10 GB per month (that works out to a little over 14 MB per hour). Upgrading to a paid Pro account for $25/year removes the bandwidth limit. I couldn't find any relevant restrictions in their terms of service.

Amazon S3
Amazon's S3 service allows you to direct-link files at a cost of 15 cents per GB of storage, and 20 cents per GB transfer. It's unlikely that would add up to more than the ~ $2 / month that seems to be the going rate for the other unlimited bandwidth plans. It has worked well for at least one other site.
I like ImageShack a lot, but it's unsuitable for any kind of load, due to the hard-coded bandwidth limit. Photobucket offers the most favorable terms, but Flickr has a better, more mature toolset. Unfortunately, I didn't notice the terms of use restrictions at Flickr until I had already purchased a Pro account from them. So we'll see how it goes. Update: it looks like Amazon S3 may be the best long-term choice, as many (if not all) of these photo sharing services are blocked in corporate firewalls.

Even though this ends up costing me $25/year, it's still an incredible bargain. I am offloading 90% of my site's bandwidth usage to an external host for a measly 2 dollars a month.

And as a nice ancillary benefit, I no longer need to block image bandwidth theft with URL rewriting. Images are free and open to everyone, whether it's abuse or not. This makes life much easier for legitimate users who want to view my content in the reader of their choice.

Also, don't forget that favicon.ico is an image, too. It's retrieved more and more often by today's readers and browsers. Make favicon.ico as small as possible, because it can have a surprisingly large impact on your bandwidth.

killar wrote:

Gotta give major props to Basou for coming up with this idea. I can see it being a pain to mod (unless Shinji gives us an auto updating account list) but I love it.

_

Jorlwind wrote:

The bandwidth is an issue, but a lot of that could be easily off loaded as explained in this article:
http://www.codinghorror.com/blog/archives/000807.html
The section your interested in is the first part,

putting it to an external image provider would make this idea about 30 times more economical.