FXX hasn’t really unveiled itself — the FX comedy-network spinoff debuts originals of It’s Always Sunny In Philadelphia, The League and late-night strip Totally Biased With W. Kamau Bell launch tomorrow night — but the network’s already talking about its Labor Day Warmup numbers. Seems that when you used to be Fox Soccer Channel, even a lobotomizingly long 7 AM-to-midnight Parks & Recreation rerun marathon, followed by a two- hour Mad About You exhumation will churn up enough viewers to generate gimongous ratings percent increases. This also serves to explain why reporting percent increases can so often be a mug’s game.

Paced by its Parks & Rec marathon, FXX posted primetime gains of 860% in adults 18-34 compared to September ’12 averages. And by 860% we mean 48,000 viewers instead of 5,000. In total viewers, FXX’s Find This Channel Labor-Day rerun marathon coughed up a slightly less impressive 108% increase, from 39,000 soccer viewers, to 81,000 Parks & Rec-aholics.

Comparing Labor Day to Labor Day, the results are even more stupendous: for Total Day, FXX posted gains of 1,850% in 18-49 compared to Fox Soccer Channel. In fairness, Fox Soccer Channel only averaged 2,000 viewers last Labor Day. FXX’s comedy retread-a-thon logged 54,000 viewers.

Moral of this story? It’s good to be the former Fox Soccer Channel.

Today’s lineup is a less marketable mashup of acquired series reruns and movies. On Wednesday night, however, FXX will hunker down with its signature series: It’s Always Sunny return for its ninth season at 10 PM, The League is back for its fifth season at 10:30 PM. And talker Totally Biased with W. Kamau Bell expands to five nights a week, starting that night at 11 PM.

FXX is available with the XTRA package and above.