Source : Webster's Revised Unabridged Dictionary (1913)

Profitable \Prof"it*a*ble\, a. [F. profitable.]
   Yielding or bringing profit or gain; gainful; lucrative;
   useful; helpful; advantageous; beneficial; as, a profitable
   trade; profitable business; a profitable study or profession.

         What was so profitable to the empire became fatal to
         the emperor.                             --Arbuthnot.
   -- {Prof"it*a*ble*ness}, n. -- {Prof"it*a*bly}, adv.

Source : WordNet®

profitableness
     n : the quality of affording gain or benefit or profit [syn: {profitability}]
         [ant: {unprofitableness}, {unprofitableness}]