This can increase your profit margin by avoiding platform fees.

I know it is profitable,

Some properties take years to become profitable.

These factors can play a huge role in making a property profitable in the long run.

My parents took out a HELOC loan on their house, and I managed the property with a 50/50 profit split. 

Many of my my investors started with 2 or 3 homes, used a value add strategy , and renovated or added adus or sq footage, and now 1031 into a 6 unit property with the same amount of money, but now going from about $1,500 cash flow from 3 properties to a 6 unit property that now gives him $3,500 gross profit. 

Then I would shoot for areas that appreciate the most, because when leveraging the 5% down.. appreciation will bring you the most profits. 

Can you handle all that if you have to eat from those profits?

Making a decent profit has everything to do with the right market...each and every one is different in guest avatar, ADR, and yearly revenue...the property itself, and the host and how knowledgeable they are on the STR industry right now because that is also an ever-changing landscape!  

Say you profit $200/month and you have a $20k HELOC. 100+ months to pay it off - not a good idea.