A 33% split is a little bit vague, but say a well makes 200 Bopd and 200 Mcfd (wet gas - high BTU). The 200 Mcfd (wet gas) goes to a gas plant where the liquids are stripped out. After this process is complete, you no longer have 200 Mcfd gas, you have maybe 120 Mcfd gas (now dry gas - low BTU). The remaining 80 Mcfd gas was the heavier end hydrocarbons (propane, butanes, pentanes, etc.) that were stripped out and then sold as a liquid (NGLs) - say 5 to 10 bbls - which is much more valuable than the "lost" gas. These are just hypothetical numbers. The volume of NGLs recovered depends primarily on the molecular composition of the gas. The more heavy ends in the gas, the more NGLs that can be recovered.
And yes, this is a wonderful time for NGLs. There is a lot of money to be made for gas plants (and gas-to-liquids plants where methane/ethane molecules are combined to create heavy ends that that can be sold as a liquid).
WTI - West Texas Intermediate (an oil benchmark - Brent Crude would be another benchmark for the European markets)