Ancestry.com is possible largely because of the Mormon church. There is a religious obligation in Mormonism to proxy baptize one's non-Mormon ancestors so they can get into heaven. To allow Mormons to identify these ancestors the LDS church has spent decades going around the world and making microfilm copies of birth, death and marriage records and the like. At one point when I was doing genealogy research on the East Coast I went to the local Mormon church's family history library and ordered a microfilmed copy of some birth records from the Russian Empire in Yiddish and Russian. I could then go through the microfilm and try to pick out the names I wanted.
Because much of the hard part (getting access to these archives and making copies of these records) has already been done, Ancestry just has to scan and OCR these records. My understanding is that Mormon volunteers do a lot of that work as well.
Because much of the hard part (getting access to these archives and making copies of these records) has already been done, Ancestry just has to scan and OCR these records. My understanding is that Mormon volunteers do a lot of that work as well.