PermzillaI think it's worth mentioning that the graph for signups is very misinforming. Season 1 was straight after the Highlander Community Challenge, so it was almost inevitable that signups would fall initially. Not saying that the drops in recent seasons is to do with that, but that is why there is such a huge drop at first.
Season 1 was A WHOLE YEAR after most of the teams got eliminated from the HCC.