For the user: this extension seemingly uses deceptive practices to offer inferior coupon, sometimes inputting their own brand coupon less than a discount than other coupons available while getting commission for theirs. Often, Honey declares no coupons are available even if the user suggests one to the Honey's database.
To other businesses: it steals from content creators or 3rd party websites who gain commissions when using their links when advertising/recommending by secretly swapping cookies at the last second before purchase. Either is does this by opening a quick pop-up window which it then closes before the user sees, or clicking the button "got it!" to dismiss the window Honey shows when it prompts that it doesnt have coupons available.

This addon is a scam which steal money from people

Scam and steals clicks from genuine referrals

scam

Steals money from referals by replacing a genuine refferal cookie with its own, even if it fails to find you a discount. This is fraud.
It will also hide the best codes to maximise the comission it recieves as a portion of the sale. This is misleading the customer.

rarely finds a discount, can mislead for a worse discount than available, steals money. FRAUD.

It's a SCAM, do not use this extension. IT'S A SCAM!

A scam

It's a scam. Steals affiliate links and doesn't even give you the best codes (sometimes no codes at all).

Scams content creators by swapping affiliate links and cookies of said content creators with their own.

Scam

Absolute scam

Always deceiving customers