Here's my question for the experts: if a large, reputable site links to mine via a clickable image, and that image has an alt tag with my keyword in it, does it help my ranking in google for that particular keyword?
Not as anchor text in a link. but having an alt text is better than not having it. You can say it's one of safe practices link builders usually do.
Man. It's amazing how fast a thread can degenerate into a dump for new users trying to inflate their post count by writing 10-word nonsense statements.
havin alt tags in images definitely gives you an edge.. but doesn't contribute a lot.. i think it might jus make a contribution of 0.5% to your rankings.. Let me show it this way.. if a text link with targeted keyword as anchor text is 10 then I would give 1 to an image linking to your website with the targeted keywords as alt tags..
And they still keep doing it after the actual answer is given and accept by OP and the OP makes the above quoted post.