Imbalances between the number of available women and the number of men desiring partners created a demand for immigrant women.
As a result of this imbalance, a new system of "picture brides" developed in predominantly male settlements.
In the twentieth century, the trend was towards women living in developing countries seeking men in more developed nations.
In the twenty-first century, the trend is now based primarily on internet-based meeting places which do not per se qualify as mail-order bride services.
One of the biggest international dating sites, based on the market share, is Anastasia Date.
International marriage agencies are frequently referred to as "mail-order bride" agencies.
Mail-order brides work with "international marriage agencies".
An international marriage agency (also called an international introduction agency or international marriage broker) is a business that endeavors to introduce men and women of different countries for the purpose of marriage, dating, or correspondence.
Marriage is a substantial part of Russian culture, with 30 years being the age at which a woman is considered an "old maid".
Many of these marriage agencies are based near women in developing countries (such as Ukraine, Russia, Colombia, Brazil, India, China, Thailand, and the Philippines).
International marriage agencies encourage women to register for their services, and facilitate communication and meetings with men from developed regions of North America, Western Europe, South Korea, Japan, Australia, and New Zealand.
The majority of the women listed in the twentieth-century and twenty-first-century services are from Southeast Asia, countries of the former Eastern Bloc and (to a lesser extent) from Latin America.
Since the collapse of the Soviet Union large numbers of eastern European women have advertised themselves in such a way, primarily from Russia, Belarus, Ukraine and Moldova.
Very few women lived there at this time, so it was hard for these men to settle down and start a family.