The Washington Post reports that there are now two categories of "really big churches":
Megachurches attract 2,000-10,000 people per weekend.
Gigachurches attract 10,000+ people weekend.
Since these are Protestant worship services, I assume this involves parallel, rather than serial, processing....
But seriously, The Post also notes that the venerable (!) Willow Creek Community Church (17,000+ per weekend) has lost its flagship status to Lakewood Church of Houston, TX, which attracts more than 25,000 people each weekend.
The mega/gigachurch phenomenon is expanding faster than ever; reasons, according to The Post, include
the surge in evangelical Christianity; the trend toward high-energy and high-tech worship; national seminars for church leaders on how to improve programming; and the range of small-group opportunities for Bible study, emotional support and other purposes that a large congregation can provide.
So people are attending ever-larger congregations in order to take part in ever more individualized niche-marketed small groups. What happens when the Mall of America meets God? (Actually, there
is a church at the Mall of America.)
[The Post notes that the U.S. has yet to catch up with Korea, Chile, Argentina, El Salvador, and Indonesia, where multiple churches report weekend attendance above 20,000. In Seoul, the Yoido Full Gospel Church has 800,000 members and attracts 100,000 per weekend (in three locations).]