Unfortunately, 10 bucks for a first cut isn't much of a special in my area. At any given time, there might be 2-3 guys offering this service. Numerous guys are doing a full service job for 24.99 on a standard 35-50 dollar yard.
For the type of people that would use a lawn service, they are already prepared to spend the $50 every other week for lawn service and don't go around trolling Craigslist and coupons for some special deal.
Considering the amount of time and money you would spend doing, the ROI is very little.