It's all smoke and mirrors really if a house is sold for £100,000.00 and you are paying 1% to the agent you get £99,000.00 from the sale.
If the buyer is willing to pay £100,000 plus the agent fee - £1000 - you get £100,000.00 BUT then the buyer would have been just as happy to pay £101,000.00 for your house and you would have got £99,900.00
As I said it's to make the deal look more appealing - although I work for a few estate agents (nothing to do with house sales) and as said above on a lot of sales they do earn their money, by the same token sometimes they do very little for a good return, but like everything they are there to make money, We have been through a lot of property both investment and as a home and apart from 1 investment property we heard about by word of mouth we have always bought and sold through an agent.