I have an American Express Credit card with USAA. One of the perks is a free "Home Value Monitoring System." The service is about as useful as a Zillow Zestimate. Basically it's unreliable and should not be used to determine anything.
The value of my home is actually 10% higher than the "VALUE" they have on their website. Like Zillow, USAA and American Express have no access to comparable sales in the state of Texas as we are a non-disclosure state. The guess they provide is simply just that, a guess.
When I called customer service today I asked how they came up with the value of my home. The rep had this to say... "You can call like a Realtor over phone and they'll do it over phone in like five minutes. Hold on, she sayin' it's on the screen, that's how we know."
When I asked who "She" was I was informed it was a loan originator. 3 or 4 minutes later the Loan Originator informed me that the valuation on MY screen was "just an estimate" and that it's a number that comes from the average home sale in my area.
On USAA's website it says this about the evaluation they provided on my homes value...
"What a buyer would pay for your home in today's market."
"Use this as a starting point to determine your available home equity."
Simply put, don't rely on your credit card or any entity that does not have access to the tools and data required to provide the best answers. More importantly, make sure the person who helps you is the local area where you are considering making an offer or selling your home.
Like I mentiond above, the estimation they provided me is off by more than 10%, or $30,000.00. Accuracy matters.