It ended up getting U.S. Border Patrol Agent Brian Terry killed on December 14, 2010, and let Mexican criminals get enough guns that they were found at over 150 crime scenes where Mexican citizens were either killed or maimed. And some of the guns were used in the November 2015 terrorist attack in Paris at the Bataclan. But other than that, it turned out just fine.
(In case you're not picking up on it, we're laying on the sarcasm very thick right now.)
You probably know what was officially called "Project Gunrunner" as "Operation Fast and Furious." Started under George W. Bush, this ATF policy audaciously grew under President Obama and became indicative of the perceived attack on American gun owners by both policy makers and their friends in the establishment media.