'Saved'? Site Lets You Send E-mails Post-Rapture

"The section used to attract subscribers left me cold. However, it does reflect the potential of a market that may reach in excess of $10 billion in the next few years," Maresco said. "If there is an opportunity to market a product or, in this case, a service to the Christian demographic, then someone will find it, develop it and ultimately market it,"

Michael Budde, Depaul University political science professor and author of the book "Christianity Incorporated: How Big Business is Buying the Church," is similarly skeptical.

"It's hard to know whether this is the church of P.T. Barnum and a sucker is born every minute or whether this is a rather curious take on what the church needs in this particular type of place," he said. "I can't see this turning into a particularly big presence because, for the millions of people this fits with, to send e-mails to the left behind — I'm not sure this is going to be worth $40 to them."

Will the Web Even Work?

Despite its infiltration into pop culture, the idea of the rapture as depicted in the "Left Behind" series is a fairly new development in Christianity, according to Randy Maddox, a theology professor at Duke divinity school.

"The understanding of the rapture as a time when Christians are taken out and [others] left behind is not a universally accepted Christian belief," Maddox said. "Indeed, the model that this Web site [promotes] is something we don't find in the Christian church until the end of the 19th Century. It's a small subset of evangelicals who have adopted this."

Similarly, the catastrophic narrative that the rapture invokes doesn't jibe with the idea of a fully-functioning Internet.

"In one sense, they're arguing it will be a time of great disaster, but in another sense he's saying, 'I promise my Web site will be working,'" Maddox said. "There are logical incongruities with the model, and there's basic theological incongruities."

'This Is Someone Who Wants $40'

Several things rang alarm bells for Amy Frykholm, author of the book "Rapture Culture: Left Behind in Evangelical America," a scholarly look at the "Left Behind" series and a writer for "Christian Century."

While Heard's site claims to be "for Christians by Christians," it never identifies who is running it, a point which Frykholm said made her instantly suspicious.