I know many people are against pop-unders, but I decided to give it a shot.
(I hope this is not concidered spamming, but I can't find another way to do this...)
Could you go in on my homepage at www.appsoftheweb.com and have a look at the pop-under.

Is it good, or do you think it hurts my "image" to have it as a pop-under?

How would you do it if you were in my shoes?

Hmm... At least it only shows once per session and isn't as bad as a popup.
Personally I would say get rid of it, just because I absolutely hate popups and popunders. As an interent user I feel that a website should have no right to open software on my computer (whether its other programs or just another instance of a program I already have running).

I know the payments from popunders can be very high, but as long as webmasters are happy to place them, we'll never get rid of them.... So I'd say get rid of it, but if it's the only thing keeping the site running, keep it up.

a timed popup or popunder like every week or at least once is month won't hurt

I hate pop ups and pop unders...........Hate em Hate em Hate em!!!

IMO, popunders are worse than popups. Especiall for those with their browsers maximized...especially for those on a mac where there is no task bar at the bottom.

Whether pertinent information or not, popunders are never good for a site's reputation because (1) it's annoying, and (2) since it's popping under, it comes off as trying to either hide something from your users, or trying to be sneaky...which kind of goes hand in hand with trying to hide something.

Also, with more and more people (myself included) using popup blockers, I don't even know that your popup will reach half your visitors.

Just my 2 cents.

There is definitely a general sense of negativity regarding pop-unders (and to a slightly lesser extent popups).

What are you trying to achieve with the pop-under? Let us know...there might be more effective alternatives out there.