The idea that call colding sales is an effective mechanism for most businesses is distinctly out of date, and has been for some years now.
Online intros via sites like linkedin are much more in vogue.
Depends on the industry. Though Facebook/LinkedIn are very valuable tools to make that first warm contact. But don't depend on them. The key is to use a combination of online and offline tools. So, introduce yourself on LinkedIn, have a nice email chat, then meet on a Skype/phone call. When you are done, send them a nice card through regular mail.
I'm sort of surprised it did not mention gethuman (http://gethuman.com/). Been around for some years now.
After not being able to find the phone number for a large audio visual company, an admin I worked with searched for the company name using Google Maps and found both the 800 and local phone numbers.
Clutch post! Wish there was something like this for smaller app developers as well.