A closer look at the box office numbers for "Pirates of the Caribbean: On Stranger Tides" shows ticket buyers are choosing to avoid the 3D mark-up.

"Pirates" drew less than 40 percent of its opening weekend audiences from 3D -- way off from "Avatar," and considerably less than other recent family-oriented titles like "How to Train Your Dragon" and "Shrek 4."

Market researchers say people have started to feel burned by substandard 3D, and are staying away -- especially as the mark-up increases -- $14 for IMAX 3D as opposed to $7 or $8 for 2D. That bias against 3D appears to especially hurt movies like "Pirates" that are actually filmed in 3D (as opposed to shoddy post-production conversions). Exit polls for "Pirates" show that those who saw in 3D liked it better than those who saw it in 2D.