Widgets and buttons with backlinks

I've had success creating quality buttons and certificates to get backlinks.

I also made widgets, mostly quick fluffly quizes, that linked back to the source.

I read a story about Google discounting backlinks from widgets if they are not relevant. A quiz about horoscopes should not link back to a pharmacy website, eventhough they made/commissioned the quiz. (can't find the story right now, sue me, no dont really read it here: http://www.seomoz.org/blog/widgetbait-gone-wild ).

I am in the process of finalising a recruitment widget. Is a mixture between promotion/advertisement and usefull nichespecific information, and uses interaction, so I wont call it a mere advertisement.

Now it would be possible to backlink this widget, a lot like Google Maps is in an iframe and below is a plain text link "look at bigger map". I estimate this would create an enormous number of backlinks.

Would you feel safe using such a strategy? Is it walking on thin ice? Anyone else used this kind of link strategy (offering widget content + backlink) and had problems? Is it against TOS/guidelines?

I would be comfortable if all of these are true....

* the widget's topic is relevant to my website
* I offered it freely to anyone (I do not pay them, they do not pay me)
* the widget has one link that points back to a relevant page on my website as attribution
* the widget and the link are both in the same frame
* the link is clearly visible to visitors
* the anchor text of the link is not KW optimized text

Tyvm for your views, very valuable.

If I leave out my goal of adding links for PR/linking strategy, but focus on users alone, I will probably not place the link in the first place. I think that answers my question for what Google's stance is on this.

I think I will provide a clear noscript fallback, and not use a link but plain text, much like GetClicky formats their tracking code with a:
<noscript><img alt="Clicky" src="http://in.getclicky.com/*.gif" /></noscript>

That way many webpages will still name the website, just not link to it. If I decide to use a link for any purpose I really think the best is to nofollow it anyway, to remove any doubts of manipulation.

The point you are talking about is classified among the link baiting options and practices and in most cases some great results could be achieved. Some websites which are now having PR7 and over have managed to reach their present state by providing some free tools and other things for their web visitors. The links are important and so try forgetting about the images Alt+Title+Anchors as they will look better.