The quality of the letters you receive depends only on the agencies, which would receive your profile. A Russian agency would not bother with sending your information to a hundred agencies - it is too expensive and troublesome.
Almost all marriage agencies place their clients' profiles in club agencies. Such a placement gives a fast effect, the women gets letters and cannot blame the agency in lack of replies. Many women, especially those whose chances are low, are deeply disappointed after contacting a Russian agency: yes, they get letters, but their correspondents disappear after 1-3 letters. Meanwhile, the women pay considerable (in their terms) amounts of money - the agency fee, postage fees, translation fee, etc.
The reason for that is that the first letter from a man is sent by the agency free of charge, but he has to pay for subsequent letters of for getting your address. Many men have no idea about this when they send their first letter, and when they do find out, they decide not to spend money.