maybe".I use them for investing all the time, but under very special conditions...and within a very tight, inflexible window.The basic conditions is that they are:\1 - Business cards2 - Have 0% interest for at least 6 months (preferably 12)...this establishes that "inflexible window"3 - 0% interest must apply to new purchases AND transfers4 - Must have at least 1/2 of the available credit able to be used in a "cash advance".5 - Must be at least 3 different (preferably 4) cards.Process of use:1 - Use the Cash Advance from the cards to buy property (this is a "cash like substance")2 - Immediately transfer balance from the Cash Advance to one of the other cards thereby eliminating the high interest rate you have on cash advances.3 - Use the remaining balances on the cards to pay for the rehab, etc...

The benefits really depend when counted against how much capital gains you will face versus a decrease in flexibility when buying a new property.I would buy a rowhome I can legally subdivide into two units in a desirable area with a strong tenant base though!

Instead of an inflexible long term mortgage take a look at flexible HELOC options.

This class always intrigued me because RE Investing variables (type of asset, period of ownership, leases, structure of ownership, ETC) can vary dramatically while lending options tend to be more rigid and inflexible in nature.As an RE Investor or as a RE Lender, what lending products or changes in lending products can you think of that would change RE Investing for the better. 

Here's the caveat: if you're late paying, the Seller may be rigidly inflexible and begin filing foreclosure when you're one day late.

So we’re not entirely inflexible on that. 

This works fairly well when it comes to holding the properties over time but I have found it to be a little inflexible when it comes to utilitizing any of the equity in the properties.  

However, I realize it might be difficult to find someone who could work with my inflexible schedule.

@Ryan Wewerka,Unlike private sellers, REO holders tend to be rather inflexible.

They are so inflexible they forced us (with threat of cancellation) to initial and agree on the contract in writing to use their closing/title company even when the bank agreed in writing on an email to allow us to use our own title/closing company because, "there are NO changes to the contract".