No big stars. No easily-marketable assets. It's just Producer J.J. Abrams and his box.
This quote, in Entertainment Weekly, from Cloverfield Director and long-time Abrams friend Matt Reeves:
"The very idea of a box,
and wondering what's inside a box,
is just as engaging--if not more so--
to J.J. than the actual contents
of a box."
Obviously, it's equally engaging to filmgoers...and to faithful FOPs (Friends of Pow!).