Look how old this is! I post at SearchCommander.com now, and this post was published 17 years 9 months 10 days ago. This industry changes FAST, so blindly following the advice here *may not* be a good idea! If you're at all unsure, feel free to hit me up on Twitter and ask.
Knowledgeable search engine experts tend to agree that ALT tags are no longer a relevant ranking factor for any of the big three search engines.
If that’s the case, the same as meta keyword tags, then why do so many page one websites still use them?
If that’s the case, then why are ALT tags still indexed by the search engines?
If that’s the case, then why do search engines follow image links, and assign relevance of that link based on the alt tag?
Even though the advantages of alt tags have diminished over time, I’m still an SEO holdout that believes they can help make a difference.
I still recommend it taking the extra 10 seconds it takes when creating a webpage to add a relevant and keyword rich ALT tag to a primary image.
I’ve updated an older article of mine and placed it in my SEO-101 area, providing some ALT tag tips.
As recommended by Search Engine professionals worldwide, ALT tags are TO BE USED. I would like to line-up-and-shoot anyone who claims that ALT tags are not useful. Okay, maybe that’s a bit harsh.
Point being: ALT is a perfect spot for mispellings of your keyword phrase, lateral keyphrases (phrases that are ‘related’ to your core keyphrases. Apple: Apple Pie, Green Apple, Apple Computer, Fiona Apple?)