Still looking at digital market places, I find that REA story is probably easier to get that the one of carsales, at least in Australia.
Both companies have a large market share in their respective market. However, it seems that there is a major difference : all of REA business comes from individuals (via property agents) while carsales business comes both from dealers (51 % of their domestic business) and individuals (22 % of the domestic business). The issue for carsales is that they have much higher yields with cardealers, while car dealers are regularly losing market shares vs individuals on the used car market.
That may be one reason why carsales seemed to have a limited organic growth : CAGR of 7 % during FY 19-FY 21. Acceleration to 16 % for FY 21-FY 24, after more development overseas (?).