If we're accommodating the running of a full bitcoin node and this costs $5/month in cloud server fees (I have no idea if this is accurate) and your servicenode receives say an average of 2 payments/day (770 max nodes to start) at 30 percent reward rate, or 120 spr/month, this could definitely work with a bit of profitability.
$5 in bitcoin= .0205/120 spr reward per month= .00001708. If the price of bitcoin remains constant and the price of spr increases to .0003 where it has been for a large portion of its lifespan, you would initially net $3.53 in profit/month per node.
IMO It should be obvious sooner or later SPR will be worth more .0003