I would have to disagree that fletching is not profitable. It is not my sole source of income, but certainly a welcome one. I'm a druid, but I always adventure with a ranger friend of mine, and keep her well stocked with quality arrows. Keeps our costs down. =)
However, I also carry around at least 40 of each component for 1/150 arrows. If there is some down time, I'll auction them off at 10pp / 100. It costs me less than 2 pp in most cases to buy the components, and at my skill level there are generally 1 or 2 failures in 40 attempts for these arrows.
I'll grant that there aren't a whole lot of tells, but on occasion I'll get a couple. And really for me, it doesn't matter, I know my Ranger friend will be able to use them if I don't sell them. I've also got a couple of regular customers who will buy from me whenever they are in need. I usually sell to them for close to cost, and being able to port and gate makes it easy to get to my customers. The key is to not expect to make a living at fletching, but to be able to supplement your income.
At 7th level I made a run into Kith at night to sell arrows to a regular, (45th Ranger) who gave me 50 plat in danger pay in addition to the cost for the arrows. He's gotten free arrows ever since. =)