I work for Packt and this campaign has caused huge traffic surges for us. Please be patient as we are working on the issues and the sign up is running until 8am Monday GMT.

The offer is for one of any eBooks for free, and can use the library PacktLib to browse and review books before choose. You only need to login/register before Monday but have a week to choose your book.

It appears to be up now, but I would expect they got a surge of traffic that might've knocked them out when you were trying.

search not working. will try again later.

Site's crawling for me and registration seems to be down. People like free stuff.

Yep. If this was some sort of marketing stunt. It worked.