(commentary)
Headline for Nikon's mass email today: "Check out the latest Large-Sensor Compact from Nikon."
Well, that gets my attention, as I like large-sensor compacts ;~). So what's this "latest" one from Nikon? Turns out they think that the 1/1.7" sensor Coolpix P7800 sensor is "large."
The P7800 has a 1/1.7" sensor that is 5.7 x 7.6mm in size, compared to where most people think that "large" starts, which is 9.6 x 12.8mm. Because sensor area is the big factor in sensor performance (all else equal), we're talking about 43 square mm versus 123 square mm. See how that 43 isn't nearly as large as the 123? Further, some people have a higher standard than that for "large," typically either m4/3 (243 square mm) or DX/APS (384 square mm) size. So it ain't "large" Nikon.
Nikon had been using a lot of 1/2.3" sensors, which are 28 square mm, so perhaps Nikon meant "larger than before." But then again, one of the lines in the email starts with "as a D-SLR owner" and speaks to image quality, so they certainly are trying to get you to equate the P7800's small sensor with their DSLRs large sensors.
One of the things that consumers have to do is sort through all these specious claims in order to choose a camera wisely. I'm picking on Nikon here, but I've seen virtually every one of the camera companies come up with zingers like this one. Caveat Lector.