It's worth it.
I'll be buying one soon. I used to have a similar resource years ago called "Songwriter's Market" or something like that, and it was a very good resource.
You "could" find much of the information contained within that book these days on the internet, but it would be a HUGELY time consuming process, especially getting the emails, phone numbers and addresses of literally thousands of places.
This puts it all in front of you in a logical fashion.
It also contains articles and how-to's on the music industry.
They have partnered with MANY respectable industry businesses, so it is not a scam. However, you should realize that MANY places DO NOT allow unsolicited material to be sent to them though, and I suspect that this book will tell you which ones do and which ones do not.
You can learn a little more here:
http://www.wikimusicguide.com/Indie_Bible
Good luck.