Real estate commissions can be costly for two reasons. Firstly, they incur considerable costs in marketing your home to prospective buyers. These include marketing and advertising the property, arranging professional photography, spending time holding open houses, negotiating offers, facilitating meetings with potential buyers, and completing documentation. Their clients don't directly reimburse them for these expenses should their property fail to sell. Secondly, real estate agents must cover a wide range of operating costs, such as office rent, general advertising, insurance, and professional association fees. Hence, the commissions they charge need to sustain their entire business.