I was surprised to see that uclue.com had gained 10,000 inbound links in the last month.

A quick look at the Google cache showed that Google is indexing Yahoo text ads (served as "sponsored links" by Overture).

I'm astounded that Google can't (or won't) exclude these transient links from its index. We expected our Yahoo ad campaign to bring us traffic from clicks on the ads. We didn't expect it to bring us thousands of inbound links indexed by Google.

Example of the snippet, and the Google Cache:

http://img144.imageshack.us/img144/9916/snippetuq0.png

http://img95.imageshack.us/img95/5827/links1ln1.png

I wonder if these transmit PageRank? Then it would be like Yahoo text ads can serve as paid text links for SEO.

Unfortunately when I go here
http://209.85.135.104/search?q=cache:T6D9ZIMnWE4J:www.researchhypothesis.com/+uclue+%22fast,+low+cost%22&hl=en&ct=clnk&cd=1

... and check the link (which is not nofollowed), it points to a redirect which has expired by now:
...researchhypothesis.com/site/redirp.htm?p=28&ws=155&enc=1&v... etc.

However, if those were sending a permanent redirect header they might also transmit linkjuice.

Oops, I didn't quite get that right, but it's worse than I thought!

The ad above is actually AdWords. Google is indexing its own ads, even though they only appear fleetingly on the page and are of no relevance to people searching with Google. Surely Google realises that pagead2.googlesyndication.com should not be indexed?

This makes AdWords into cheap paid links, in addition to the ad traffic that they might bring.

Here's the Google cache of the page with the ad:
http://66.102.9.104/search?q=cache:6-0SWdqmtcYJ:www.researchaccounting.com/+link:+uclue.com+site:researchaccounting.com&hl=en&ct=clnk&cd=1&client=firefox-a
which can be found by doing a Google search for
link: uclue.com site:researchaccounting.com

Although I posted the wrong link in my previous message, Google IS also indexing Yahoo ads. Here's an example from the cache:
http://66.102.9.104/search?q=cache:NHRQu9xTL1UJ:sc2tc.mojolingo.com.tw/m2m-0000/health.yahoo.com/experts/healthnews/4285/notable-changes-in-cpr-guidelines+link:+uclue.com&hl=en&ct=clnk&cd=38&client=firefox-a
and it can be found by going a Google search for
link: uclue.com "CPR Guidelines"

I don't think I can reproduce the first bit.
[link: uclue.com site:researchaccounting.com] seems to not be the link operator, but just a search for the word "link" (because there's a space between "link:" and "uclue.com – remove the space and there will not be this result). As the page contains the word "links", Google does stemming and even highlights the word "links" on that page. And if we check the target of the links, they're going through a redirection which is hosted on pagead2.googlesyndication.com, and the robots.txt file of that domain reads:

<<User-Agent: *
Disallow: /
Noindex: />>

Hence, maybe this redirect wouldn't be a "spiderable link juice" because bots are forbidden (sort of like nofollow)?

I think you're right, Philipp, it's probably not link juice.

I still don't think there's any purpose to be served by indexing transient text ads though.