Here’s one of their success stories (name changed for obvious reasons):
I've been in networking 15 years, worked my way up through CCNA (2001) → CCNP → CCIE (2011), been an independent consultant since 2006 and started a perm role for a vendor last year. I've never been a mono-vendor evangelist and in fact I've used less Cisco than anything in recent years (you realize how well they do some things but how indoctrinating they can be when you pull away a bit I find) so I've always used your material (and Packet Pushers) to give me a broad view of products, features, protocols etc. and this has ultimately made me a better engineer and a much better designer / architect.
You've helped me get numerous contracts over the years as well as my current perm role for a vendor! I've been approached by another vendor now, guess whose material I'll be reviewing as a background info and refresher material before my technical grilling? ;)
As we all find our feet in this new automated, software driven world (although I'm sure IOS is software and I've been using this for quite some time :) I believe the more independent voices and material available to read, consider and be influenced by, the better chance we have of doing things right, rather than what vendors want - so you have a customer for life here!
Do you have a similar story to share? Write a comment or send me an email. Thank you!