Ref Lori's post. It may be the seller paying the fees (on paper), as many adverts proclaim but in effect it's always the BUYER who pays. This is because only one party is paying in money and that would be the buyer.
It's also the case that sometimes the agent agrees with the seller to take a lower fee in order to have the sale go ahead. While the agent would like the full fee, it's also reality that when a property sticks on the market, they get nothing. In times of buyers' market, the agent often agrees a lower fee to enable the sale to go ahead.
The seller still gets the price they want, the agent gets their fee (albeit a bit less than they'd like) and the buyer gets the property because after all it is always the buyer who coughs ALL of the money;