What is the value of hosting assets on Amazon S3? Best practices question Starting a substantial project. There will be 100s of images on the site. Few are part of the general design, but there are slide carousels, photos, etc.

I understand what S3 is, but I'm wondering what the specific value is of using it over local storage. There is plenty of room on the web host's server. 

S3 isn't a CDN, right? Or will it replicate files across to other locations?

Should I expect S3 to be faster than local storage? And is my S3 bucket backed up elsewhere, should Amazon's servers crash?

Thanks.
S3 is not itself a CDN, no.  However, you can use Cloudflare as a free and very easy to set up CDN service in front of it.

For me the main advantages of S3 are that it's a centralised repository of assets I can point all my environments to (so dev, staging, production all point to the same S3 and thus have identical assets available to them with no need to sync anything).  I trust Amazon to runs servers more than I do individual other companies, simply by virtue of their size and experience (and I know some of the engineers as well - they're smart people!).

With Cloudflare in front of S3, you get CDN and static asset caching benefits, and images are served very quickly.