Do image links with no alt tags pass link value?

[Jeepster]

"... an image link with no alt tag is useless to search engines..." according to a Nov 2007 seomoz blog post. Is this still the case in 2011?

I ask because I'm about to obtain a banner link on a high-traffic site (chiefly for the clickthrough value) but I notice the site uses neither "title" nor "alt" tags.

[GeorgeDavis]

As Rebecca pointed out right after that statement, Google is able to pull the context around the link and probably the context of your own site to determine the value of that link but it's definitely not desirable.  If you can I would push for an alt/title tag.

[RyanPurkey]

It's not really useless as there is page rank passed through most links on the web to some degree, it's just harder to classify what the image means in a keyword sense.  Also, if this is a banner link, there's likely to be a redirect script or discounted link value because you're paying for the placement anyways.

If you do acquire other image links though, having the image be in a table cell with related text nearby helps, having the image and text be part of the link also heps, if the image is in a div or other markup along with related text, that helps too... Basically anything that correlates the image to some text in a common web structure.  And of course, alt or title text.

[Mr.Rangen]

Maile Ohye stated (at SESSF 2010), when an image is linking out, the alt img text is just as important as anchor text is in a contextual link. That is something to keep in mind when you are going through your link profile..

[j0a0vargas]

If your image link is FOLLOW, the alt tag may pass link value.

But it seems that text links have a value slightly higher. That at least is what I have observed. But put the alt on your images you are linking to your site is essential.