Perhaps some day we will see missionaries FROM a remote part of the world come to our town and save our neighbors.
I remember hearing a preacher a few years ago saying that Africa sends numerous missionaries now to the United States. Our church has had a couple visit us.
In regards to translators, the assumption with a radio or TV ministry is to reach people for Christ. Translators are far less expensive than setting a radio station in each city where the translator is located. Sure, as a former radio broadcaster, I'd like to see each city have it's own on fire for Christ radio station, but that would require far more donations.
There are many places that would not have a Christian radio station or TV station IF it were not for those translators. I live in market # 75 Wilmington Delaware and sometimes listen to Family Radio (WKDN - Camden NJ which is the nearest affiliate, they also have a translator for WKDN in Dover Del which I can't pick up) for the music (it's a quieter format than a CCM station which is a nice change of pace) and some of their programs. One feature they air is where they interview people who's lives have been touched and they became seekers of Christ and eventually came to know Christ due to stumbling into a Family Radio station (so some people other than radio geeks scan around the dial at least sometimes). My guess is the various stations do get letters and emails, possibly even phone calls from folks who are blessed by the translator being in their area. Some of those new found listeners be they already saved or newly saved probably do donate to help the cause. I don't agree with all of Harold Campings theology, but given the fact that he's got stations/translators all over America and stations around the world in over 30 languages is testimony to how God can use a radio ministry such as Family Radio or any of the other Christian based radio networks. Praise God for these various radio out reaches. If one person is reached for Christ and it would seem that more than one has been reached for Christ then it's worth it.
It isn't only Christian stations that heavily use translators, secular non-comms do as well. An example Temple University's WRTI - Philly, is a Classical daytime and Jazz nighttime station. They have numerous translators in PA, NJ, and Del. If they didn't, then those communities wouldn't have Classical music or Jazz available to them on the radio. The translator is a less expensive way for those specialized radio broadcasters to serve a larger community with programming that generally isn't available on the commerical stations. This does seem to serve the communities both secular and religious.