Also having different debit/credit cards is very useful when you have one declined for a reason or another (bank network down, or blocked for your purchasing pattern that trigger their security algorithm).

They are continually improving their algorithms and I have definitely noticed it an improvement in the accuracy of their data.

One cool company that I know of based out of NYC has a really awesome algorithm that identifies undervalued MF opportunities on the open market in addition to predicting future returns. 

@Victor Fermin There is a new company that has some slick algorithms using live supply and demand data called https://shivatech.ai. 

The algorithms  they use are not specific to certain features that add or lessen value to a property.

Sometimes Zillow et al will "remember" what things were, so I have even had to fool their algorithm by changing the address by 1/2 (i.e. 102 1/2 Main Street) just to get past their recorded algorithms.

If it's that important to you, use a pricing algorithm like Wheelhouse or BeyondPricing etc. 

If you get audited on a algorithm based study you just have to pay for an engineered one.

Any online system is using an algorithm and data from properties recently sold or currently on the market.

No algorithm can evaluate the interior condition of a property and determine an ARV.