It boggles the mind how much economic rent and inefficiency is gotten through pointlessly proprietary formats.

And Sony in particular has tried it many, many times, and usually failed.

Beta, 3.5" floppies, Minidisc, Blu-Ray, Digital8, MS...any others?

Proprietary ATRAC music file format, as used with MiniDisc and their other portable music players.

however, if they get traction they can win big time in profits and vendor lock-in.

i agree with you, however.

Vendor lock-in is a form of economic rent.

Sony decided a while back to drop memory sticks and use only SD cards moving forward. Even the X10 had an SD card slot. It might have been around the time they announced the X10 now that I think about it, not sure...

This is a Sony-Ericsson product, not a Sony product. I don't know if Sony-Ericsson has ever used Memory Sticks in their products. Certainly non of them have for quite a while.

They did use them. All the sizes down to M2. But they recently switched to microSD as well

My K810i had a M2 slot