Unless one is making an argument that the seasonlity has been removed from the business model (General Bucha didn't make it) then, IMO, it's unwise to take $66M run-rate and divide by 4 because... seasonality.
We've been given 2018's expectations: $90M to $110M gross = $80M to $100M net. The $66M isn't an extrapolation of "future performance". It's an extrapolation over past, or 2017's, performance.
We know the following (big round numbers for simplicity's sake):
$10M = Q4 2016
$10M = Q1 2017 $15M = Q2 2017 $15M = Q3 2017
Notice how Q1 and Q4 = 40% of annual revenue? Q2 and Q3 = 60%?
We do $13M in Q4 2017 = $53M for 2017. $13M / .20 = $65M run-rate.
The $66M run-rate is saying a way of saying if things had been like Q4 since day 1 of 2017, we would have done $66M instead of $53M. I think it's also a way of glossing over 2017's under-performance.