What I found most interesting today is its ability to capture and graphically report market-value on existing gems (whether uncut, perfect, epic) by color. This makes is easier to know what could potentially sell on the AH with your Jewelcrafter instead of mindlessly burning through cuts without understanding their sell points. This gets refreshed every hour like the statistics do. Obviously this is all point-in-time and doesn't last over time so frequent visits to see what's hot is important. Have you bookmarked it yet?
Check this it out - even with color coding to help you identify what's selling/cost quicker.
An excerpt from TUJ explains the colors: "A blue background indicates that gem is selling under 75% of the price of the uncut gem. A yellow background indicates a gem selling for 1.5 times over the uncut price, and the red background indicates a gem selling for 3 times the price of its uncut counterpart."
This picture only shows the Pandaria Gems but it lists them all from Pandaria, Lich King, Meta Gems, and more. Overall, I'm finding as mentioned in an earlier post, perfect gems sell at a pretty decent rate/value (~50-300g/ea) as well as uncut Cata gems in stacks (100-800g/stack), but the normal gems are a tough sell unless you're willing to dump at a low price. Personally, I drop these in the guild bank in stacks of 20 for new toons coming up. Since this market changes SO MUCH and there is SO MUCH competition, I would recommend a 12-hour listing on the AH too. Spend as little coin as possible listing because you might be listing them several times before a sale is made which all eats into your bottom-line profitz....I mean profit. ;)
Game Hard! Sell Harder!