Online Soccer Manager (OSM) was created in times when Hattrick and ManagerZone were still far from peak of their popularity. OSM went completely different way - from start they invested heavily in SEO marketing and at some points it was hard not to stumble upon one of their many domains. The game itself was rather simple and the whole outlook of the project was appealing mostly to younger fans.
But that was not the only detail that was different with that game - with time they also gained licenses to use real club names in few countries, as well as licenses to use real life players names. It was unusual for two reasons - on one hand it meant that, unlike in their competitors, in OSM you could take control of Real Madrid and be in charge of Cristiano Ronaldo or Raul, but at the same time it meant that you are not building your own team, you are just dropped into some sort of alternative reality within your game world, which puts them in category of fantasy football, rather than typical football manager genre.
But as many people know, licenses to use real club names and real players names don’t grow on trees, so it all came with a cost. Together with introduction of those elements OSM introduced elements of micropayments, where some of the options are available only if you have enough in-game currency. Also they turned the game into "free to wait" model that we all love so much - you can get report you need in one hour or you can buy it and access right now.
The game itself is not for everyone, as you do not have full control of the team, because you do not build it from scratch. The players are described by only few parameters, because the game tries to appeal to young users, not to mention the game itself lacks atmosphere.