The OH flew to Poland a couple of weeks ago with Ryanair, £5 there and £8 back, but with around 110-120 passengers. Clearly that's not making any money, but if it captures enough of the slimmed down market to prevent competitors even operating there, then it's somewhat achieving it's aim.
It's not making money if everyone is paying these prices but every passenger is probably paying a different price, some with bags, flexi tickets etc. The whole low-cost model is based on flying one standard aeroplane type. Price tickets low initially and high as the departure date approaches for those that can't/won't plan ahead of those who need business style flexible ticketing. If you can't make money, drop the route and fly somewhere else.