Zillow and their online estimate

[Edit B.]

I've listed a couple of properties that I'm flipping and noticed that Zillow(to no surprise) is maybe getting something wrong when dealing with properties that are being renovated/flipped. The "Zestimate" history seems to be reasonable up to the date of initial purchase(discounted), then re-evaluates to another value much lower than the previous for the obvious reason that you just bought it much cheaper. I think it should exclude these sorts of purchases, same as foreclosed purchases. 

When you list the property to sell you now have a significantly lower "Zestimate" to deal with. Redfin gets around this by excluding the prior sale or it takes into account the listing agents price point, not really sure but it does not have the same problem. 

I don't really care for Zillows "Zestimate"- I think its complete bs. However I know a lot people(potential buyers) who are not involved in RE do. 

Is anyone able to do anything about this?