A "dating service" is simply a euphanism for a mail order bride service.
We spent months in Eastern Europe, and there are all kinds of these "dating services" out there. That is exactly what they are. Men join the "dating service" with a very clear understanding that they go to X country, the "service" sets up a "date night" where the handful of foreign men mingle with the women (usually in developing countries, who are there to escape grinding poverty) with the intent on choosing one, much the way you'd choose a horse. Is she attractive? Slim? Will obey? Child-bearing hips? Then for the fees paid, the agency goes about guiding their male client through the legal morrass of applying for a temporary visa, arranging a marriage ceremony in the host country, etc etc.
Who uses these "services"? Men who are losers who probably couldn't maintain a relationship any other way: either through lack of personality, character deficits, they are physically unappealing, they want a woman who will cook, be a maid, shut up and do what they say and provide sex on tap. They've struck out the conventional way, so they decide to go this route for a "sure thing" who has no chance of rejecting them.
This is not match.com in a foreign country.