I just added the biggerpockets affiliation to my  home depot pro account for 20% off on paint.

The source of our data is a division of First American Title called Core Logic or RealQuest (we have no affiliation with them whatsoever).They are the industry standard for real estate mailer data for all types of real estate, in my opinion.

I paid for the boot camp and paid to become an affiliate.

Also get e mails from them to be a broker affiliate.

Or, they might be a wholesaler and doing an assignment, double close or something else tricky and they have a title company that will do the transaction.But I've not heard of a lender demanding you use a specific company.That said, this is an incestuous industry and there are affiliations between many of the players.  

updated every week with an amazon affiliate link to drive some incremental sales?

My firm is affiliated with a company called Homeland Title & Escrow.

Affiliating with a separate unrelated company in California is possible?

I'm not in any way affiliated with the company, just a customer.

However, I did not have the money for rehab, so I worked with a separate lender (although affiliated) on a 20k personal credit line, allowing me to rehab both sides and have ~10k left over (property needed the basics: carpet, paint, some drywall and appliances).