So I have a niche site that has been added to sites like boredbutton.com and boredclick.com and a few others. However the link is only ever seen when it is iframed which works out really well for free traffic .... but what is the overall SEO value of this type of links? How does google value iframed links?
I don't think there can be any value as your links don't appear in the html. Links are not always the only consideration as you say traffic is valuable in its own right.
The iframe isn't the point, readable anchor tags in an iframe are fine but as Highlandspring says if there is no html for Google to read then the link is not "seen" by Google