If you think I've missed something or have made an error, by all means leave a comment here or at the actual blog post. :)

Oh man... you don't REALLY want me to do that do ya? lol. U know me, has to be a careful decision and ensure it is worth doing for your site. Task ROI baby!

Agreed, it's one of those things you need to carefully consider if it's worth your while. However, knowing these factors can help you when you're building a site, or when you're using images on your blog. Better to do it right from the start if you have the chance, than risking re-doing it afterwards (or not at all, if the task ROI just isn't worth it).

Perhaps theGypsy meant the ROI on commenting on what you missed ;-)

theGypsy brings up a good point!  Also worth mentioning, the image extension for Sitemaps, EXIF, licensing and submitting http://www.panoramio.com/ if you want images to show up in Google maps.

Just my two cents... ;)

Well, the point was that in some cases image search referrers are nothing more than a lag on the server, baihot linkers and image thieves etc. You want to establish the prupose for wanting to get images seen on a search engine. Will it build authority? Will it help conversions? What is the purpose for wanting to be there in the first place. In short, where's the ROI for the time spent targeting the vertical. ;)

@David, depends on the site. You could apply the same logic to Google News - that type of traffic is high-bounce, high-exit as well. But news sites don't sneeze at it when pageviews are a vital metric of success (ABCe auditing for example).

Sites that make revenue off of images (stock photos, image printing, ad revenue on galleries, etc) would do well to pay attention to image SEO. Of course you need to make sure your site is sufficiently sticky to monetise that traffic once you get it.