There are several different kinds of accommodation finding agencies/services in Madrid.
First you have the Spanish ones like Real Estate agencies that charge you one month's rent service fee. Next you have "Centros de informacion" or "Oficinas" that use a bait and switch technique to get you to come into their office where they can give you their sales pitch to pay them 168 euros or more for their services and then only give you a list of phone numbers or a recording where you can hear offers they just compiled from the Segundamano newspaper and "For Rent" signs on the street.
Next you have the ones that are English and Spanish speaking, although not all 100% bilingual.
Room Mardid/Europe is the only real one that is an agency. They own a few buildings and manage several other properties as well as providing the finding service. This way they get the money for the service, which is 100 euros for a room and one month's rent for your own flat. They also get the rent money for each place at their already inflated price which includes their commision.
Next you have the people like Welcome to Madrid/Spain and Madrid Flatmate who pretend to be agencies, but have no real database of housing or accommodation and only do phone calling and appointment setting through the Segundamano newspaper and the odd offer from a landlord here and there. It is impossible to keep an acurate database of offers in Madrid because the landlords are self interested and will offer their property to everyone at the same time and rent their place to the first person without any loyalty issues at all. Making it impossible for anyone who is not the actual owner to be a real agency.
Welcome to Madrid/Spain charges 50 euros for a room search and a percentage of the rent for an entire flat search. Madrid Flatmate charges 60 euros plus tax for a room search.
Finally there is Madrid Insider who offers the same exact services as Welcome to Madrid/Spain and Madrid Flatmate without pretending to be an agency and for only 50 euros per person. The actual service that all three of the above websites do is exactly the same. It is a phone calling and appointment setting service, where the client indicates what they are looking for and when they can go on viewings and then all three companies respectively check to see if they happen to have an offers that match at hand and if not then buy the Segundamano newspaper the next day and begin calling landlords to schedule a series of viewings for the clients until they find something. The sooner the better as phone calls cost a lot of money in Madrid and the quicker the clients settle on a place the bigger the profit for the people calling.
Rocco.

Rocco. I'm going to allow this posting of yours - this time. I'm also locking the thread. Consider your statement made and leave it at that. If others have questions about XYZ Accommodation Finding Agencies in the future feel free to inform them but by your starting a new thread, volunteering this "free information" and considering you're in the same business, I don't consider this following the message board policy exactly. Please don't start any other threads like this. We don't need the person who runs Madrid Flatmate or your other competitors coming to start fights on our message board. We won't have it. Thank you and peace-out.

Sincerely, MadridMan