We have had the exit pop ups running for close on 2 weeks already without any errors
until now that is.
As far as checking our sites for mistakes goes, we have a dedicated QA team that
checks all links/banners/mailers/sites daily for errors. We are limited when it comes
to after hours monitoring but our QA team is quick to rectify all issues at the start of
every day, for those issues that may have occurred during the course of the evening.