I note that you asked specifically about “cash-flows”, which has multiple components each treated differently for tax purposes.In general, you can start with NOI, next you have debt service and cap ex, which can get you to cash-flows.The interest portion of your debt service is tax deductible (possible subject to limitations) and the principal portion is not because you get basis in the asset for the loan principal, which generates a depreciation deduction.Similarly, cap ex is generally not deductible currently but the expenditure is capitalized and depreciated, similar to the initial basis in the asset.In summary, you have cash and non-cash tax items that cause your taxable income to differ from your cash-flows and taxable income * tax rate determines your tax liability.

If you are super-confident these are solid LEADS and not just prospects, check out the cost of a messenger service to deliver your envelopes - here in my area I can get them sent same day within 4hr delivery for less than fedex next day.

I want it to contain properties, descriptions, abiliy to complete web site online, make online payments, submit service requests, etc.

They also drew up the lease, but then I took over management as that is not a service they provide. 

I already have a part-time job at the online service https://edureviewer.com/ where I edit the essay and paper-works of the students) There is a good job and living in the rent flat is quite convenient with my profession)

When offering birddogging services, do you have the person requesting the bird dogging services sign a contract to make sure you get your finders fee or is it just a word of mouth thing?

You might want to post this to a group on FB called "Say no to VRBO Service Fee". 

It works best for tech-savvy tenants, if the tenants are less savvy you need to use paper applications and process through some other service.

About 7 months later I got an email from my lender stating that the servicer for that loan, who was Wells Fargo, had gotten a loan application request from the same borrower at their local branch to buy an investment property and it listed his previous address as his current primary residence, not the one that I had just done the loan on 7 months before. 

Tenant wasn't paying rent, brought a "service dog" into the home without consent and again, left the place completely trashed.