From what I've observed flying this route occasionally, RIC-JFK loads are always packed on weekends (i.e. Friday nights, Sunday nights, holidays) but pretty light midweek. Richmond has a large number of New York-area transplants, myself included, who now fly rather than drive 6 hours to visit family/friends thanks to B6's fares. The vast majority of business travelers in Richmond still use US or DL to LGA, which generally match B6's fares. I don't think JetBlue is in danger of pulling out of RIC any time soon, but I hope RIC travelers heed the "use it or lose it" warning of the local airport commission. I have loads of miles on US, and LGA is more convenient than JFK, but I do fly B6 on occasion to help keep lower fares in the market (plus, the E190 is far more comfortable than the ERJ, and I could care less about 500 FF miles each way from US).