According to a press release, "Participating churches reported an average 31 percent increase in attendance, and 35 percent of responding churches said they had new visitors making decisions to receive Christ or to rededicate their lives."
On Sunday, more than 21,200 churches will participate in National Back to Church Sunday. The massive outreach effort—which has grown more than 60 percent from last year's 13,150 churches—is based on Thom Rainer's research that "82 percent of the unchurched are likely to attend church if invited by a trusted friend or relative," while "only 2 percent of church-going people invite someone to church in a given year."
Meanwhile, a Pew Research Center summary of recent research spotlights the main reasons Americans don't attend church:
24% cite personal priorities—including 16% who say they are too busy.
24% mention practical difficulties—including work conflicts, health problems or transportation difficulties.
37% point to an issue directly related to religion—including disagreements with the beliefs of the religion or their church leaders, or beliefs that attending worship services is not important.
But overall, Pew finds that church attendance in America has held rather steady over the past decade. Essentially, 37% of Americans in 2013 say they attend worship services at least weekly (vs. 39% in 2003), and 29% of Americans today say they seldom or never attend worship services (vs. 25% in 2003).