What is the revenue stream from those trailers worth?  

Please see Topic No. 701, Sale of your home | Internal Revenue Serviceshttps://www.irs.gov/taxtopics/tc701

And when prices are high, values UP, revenues UP, an INVESTOR grit's the teeth saying Divi's feel good but oh-boy-oh-boy feeling ready to hammer that sell-Sell-SELL button. 

The items you'll need to track are:Date of ExpenditureVendor Name/Tenant NameAmountCategory of Expense (look at a Schedule E to get this)/ or Revenue Type (Rent, Deposit, Utility Reimb, etc)Property (for when you have multiple properties.Put it in a nice column format like this:Date                     Vendor/Tenant                Amount                      Category                  Property1/1/18                   Joe Smith                         $1500.00                     Rent                           123 Main Street1/5/18                  Home Depot                   - $20.00                        Repairs                       567 Oak StreetSo that when you share your spreadsheet, they can filter for what they want. 

The revenue after expenses (including mortgage, taxes, airbnb fees, etc) was significantly higher than with long term renting. 

New rent control laws and regulations, such as the ones in Oregon, can decrease revenue generation for investors.

To register, an owner must provide a completed application, proof of ownership, designation of a responsible party, a copy of the City of Bradenton’s business tax receipt, a current and active license as a TPLE, a current certificate of registration from the Department of Revenue, an exterior site sketch, an interior building sketch, a blank rental agreement, and any pre-existing rental agreements.

You can get 15-25% of gross booking revenue, which is usually as much or more than the arbitrage margins without the risk.

You have to ask yourself the question: are you designing this space for yourself or for your Guests/highest revenue potential?

This happens every day, there's lots of marketing activity to say no to revenue, and oddly prior to anyone bringing it up you're screaming from the hilltops that Spark doesn't accept this money - well time will tell.