There are many good books out there on the subject, but a my personal favorite is one called “The Secret Life o Real Estate and Banking” by Phillip J Anderson.

The secret to living is giving.6.

Using the term "public record" might remind them that their information is no secret, and therefore, you did nothing wrong/illegal/shady in getting that information.

I don't have any earth shattering secrets you can't find in books, but I can share actual experiences, timelines, prices, rehab costs, insurance costs, rental roles, property management and tips for how I've created a 19 unit portfolio worth almost $1M and generating over $100k annually inside my IRA, starting from a relatively small initial investment.  

I've had this secret interest in real estate for such a long time, and I decided I needed to finally pursue it.

We’re going to clean super hard core tonight, but secretly we were hoping we could leave somehow

Let me know if you find the "secret" source haha. 

We just had our own personal door code and it makes us feel a lot safer with guests in the house.One of the best things we did when screening guests is we would send them a "welcome message" which reinterated rules such as-Don't park in the driveway-Take your shoes off at the door-etc.and hidden (smack dab in the middle) was the "secret code phrase" that they had to reply with to confirm they actually read the welcome message.

The "popularity" is just  a function of how many gurus are trying to make money selling you the "secrets".

No honestly there is no secret to it.