You often hear cited as fact that Mormonism is the fastest-growing religion in the world. Peggy Fletcher Stack does a fine job in a recent Salt Lake Tribune op-ed piece of sorting out the evidence that this is untrue:

Today, The Church of Jesus Christ of Latter-day Saints has more than 12 million members on its rolls, more than doubling its numbers in the past quarter-century. But since 1990, other faiths—Seventh-day Adventists, Assemblies of God and Pentecostal groups—have grown much faster and in more places around the globe.

And most telling, the number of Latter-day Saints who are considered active churchgoers is only about a third of the total, or 4 million in the pews every Sunday, researchers say.

For a church with such a large, dedicated missionary corps constantly seeking to spread its word, conversion numbers in recent years tell an unexpected story....   [full article]

(A sidebar to the article also lists other fascinating pieces on Mormon demographics, though some will only be of interest to readers familiar with Utah.)