This wont come as a shock to most of you, but Zillow is very sketchy.
I got an email from them about a house for sale not too far from me:
https://www.zillow.com/homedetails/3728-Park-Dr-El-Dorado-Hills-CA-95762/18614239_zpid/
I'm not looking to buy so wasn't sure why the email came, until I saw who owns the house... Zillow of course.
They bought the home for $707k June 8, and relisted it for sale June 28 for $790k. I get it, they are in the business to make money, but here is where things get really sketchy. In May 2021, their "estimate" on the house was $675k, in June it went up to $700k ($25k in one month seems high but things are hot around here). After they bought it, the estimate shoots up to $845k in July, making them asking $790k look like a good deal.
So shady...not unexpected at all, but shady and really means their estimates are worthless.