Some not very outdated statistics.

An article from The Industry Standard, from December, 2000, reports that

Twenty-one percent of Web surfers, or roughly 20 million people, have looked for spiritual or religious information online.

That's a pretty significant percentage. The article is based on a study conducted by Pew Internet Services. It covers numerous aspects of internet use for (usually institutional) religious purposes. A full copy of the report (in PDF) is available here.

And though this particular study reports on many and varied aspects of the religious internet, there are other possible expressions of spirituality via the computer.

Go to: So you checked. So what?, or
Go to: The Church of the Eternal Click.