It depends on the website under question. If it is a complete image directory / gallery, my traffic is phenomenal from google images.
Well, true i have a beauty site which gets tons of image search, almost 40-50% i say It is a wise idea to place images in each page with targeted alt tags
Traffic from Google images is not good, especially if it's 30%. Majority of the time these people do NOT view your site, they go to the direct link of your image to either download it or hotlink to it. Make sure to use hotlink prevention methods if your site is getting a lot of Google images traffic.
One time, at one of my sites, it was something around 10%. But it has never been that high since then.
There is a nice little javascript that breaks googles frame of your site therefore forcing the user to visit your website. i get about 300-400 uniques a day from direct traffic (which is what it shows up as if you use the script). id say a majority of it is image traffic.
Mine for last month was 2.8 % which I am happy with. I sell products from my website so I don't really need visitors that are searching google images. They aren't looking for something to buy.
As others stated it depends on the site, but also how many images you got and what kind of images you have got. For example if you have got highly searched google images on your website then you should get some traffic. My sites dont get any traffic from it appart from one of them which gets a few clicks which is little anyway. thanks.
<script language='JavaScript' type='text/javascript'> if (top.location != self.location) top.location = self.location; </script> Code (markup): really great script...try it