*buys a low prim couch for her RL living room, then finds out it is the wrong color for her decor and tries to return it by shoving it through the intertubes and fails*
 

I buy most things online, but I don't like shopping, so if a shop were in 3d rather than 2d it would be a bit worse rather than better.

I want to get in and get out in the shortest amount of time and I probably wouldn't want to wander around a sim any more than I'd like to wander around a shop.

The exception might be something that could be better shown in 3d, or which used a particular strength of SL for a genuine purpose. Lame example: several hotel rooms could be shown to scale, from a single to a suite, or whathaveyou, so you could compare.