So unless you want half your visitors to NOT have the option to close the popup box, and wait for the box to disappear, this is a great module. I know I would just leave the page though as a visitor.
If this is all okay with you, this module works great and is easy to set up.
Where did you get half the visitors numbers? Please refrain from publishing falsehoods; especially knowingly...if that is the case.
Finally, my Forum has received more than 24 issues and most people walk away very satisfied.