What sort of margins do estate agents operate on?

About 10ish years ago we had 3 local EAs in our town, of approx 10k residents, we peaked at 10 but 3 braches have closed down, so we now have 7.

One of the 7, which had the most est brand name in our local area, having been set up in 1938 has been purchased by a local chain. I found this surprising as the founder's grandchild were running the EA. I was wondering what sort of margins EA operate on?

Like most businesses, its mainly staff costs and rent, and most EA make use of Saturday / temp workers. Are we likely to see more EA going bust?