Real estate agents pay subscription fees to an MLS company which then allow property listings to be uploaded onto their servers. Also, all subscribing real estate agents create a property search link on their own websites which links directly to the MLS service. Thus, any site visitor to any of the subscribing agents' sites will be able to find all properties listed on the MLS servers, even though they are visiting the website of a single agent. In effect, every single subscribing real estate agent appears to be offering exactly the same properties for sale, not unlike the situation with IDX systems in the United States.
When buyers use the internet to find property, often using Google, the search results usually provide a list of real estate agents' websites in the locality which is being searched. The buyer clicks through the various websites and starts browsing properties of interest, although every site visited is offering the same properties because they are all linked to the same MLS server.
The buyer then has to choose an agent (again, not very different from elsewhere), but it does force the buyer to make a decision, since all agents in the area have access to all properties and the seller's agent will benefit regardless of who brings the buyer, again very like the US.
Although there are currently no regulations in Europe in relation to MLS, it may be a matter of time before its use may be viewed as a restrictive practice designed to benefit real estate agents, rather than consumers.