Which of these is correct: "Sheila is now in Facebook" or "Sheila is now on Facebook"?

Solution 1:

It's my opinion that you get on Facebook. Not in it.

Just as you are online and offline.

Sheila is online

Sheila is on Facebook.

However, if Sheila recently became a big fan of Facebook..

Shelia is now into Facebook.

I think:

Shelia is now in Facebook.

would, possibly, imply that Shelia has joined Facebook as an employee. Whereas

Shelia is now on Facebook.

would imply that Shelia, now, has a profile on Facebook.