There are many categories in Japanese adult service.

GFE like a dating club where an escort girl plays a role as your girlfriend becomes a hit through word of mouth.

You meet an escort girl at a meeting point like a station and enjoy dating with her for the reserved time.
She is a dummy girlfriend.

Service, price, and girls are different in each GFE, but most service but sexual service is generally fine.

The reason of this popularity is their service targets on men who do not have chance to contact with girls.

They do not want professional girls but want to talk with girls.
This service suits to their requirement.

Besides, most GFE cost less than regular adult service.

Actually, they are concentrated in Akihabara.

No one but you know.
People think you are dating with your girlfriend.
A user can get a sense of superiority and fulfilling time.