[Animats]

The previous poster's point is that if you can cram your problem into the limited resources of an Arduino, with its small ATMega CPU and very limited memory, it's not a big jump to a custom board for your low-cost product. Anyone can buy an ATMEGA328 CPU, the low-end Arduino processor. $1.78 from DigiKey; $1.27 at Seeed. No royalties.

[paulgerhardt]

Sure, getting your program to run on an Arduino is 90% of the work. Getting it from Arduino to production is the other 90%.