I could be wrong, but I don't think this is quite an apples to apples comparison. TV numbers are measuring the average numbers of viewers at any one particular moment. So if someone leaves the broadcast and another viewer turns on the channel at that exact moment, that equates to 1 viewer. Unique viewers would be counting that as 2 as they're just counting anyone who logs into the broadcast regardless of how long they watch.
That said, it's still really good and one has to wonder if Barstool will try to expand and cover more games a crossed D1 in the future.