cutting the fees by 25% actually. Redfin acts as the buyer or seller's broker and only gives you back half of their 3% commission. The other side's broker still gets their 3%. So you pay 4.5% instead of 6%.
They actually only charge 1% commission as the selling agent now, too, so vs a typical 6% combined commission, they save 33% for the seller. (Assuming just a sale)
Redfin doesn't seem to disclose how they calculate the refund anymore, though, so I'm not sure how much that works out to be. Seems to be around half a percent, so lower than it used to be.
All combined, it's close to half of the traditional fees that they either refund or don't collect.