Idleness is a constant sin, and labor is a duty. Idleness is the devil's home for temptation and for unprofitable, distracting musings; while labor profiteth others and ourselves.
RANSOM, n. The purchase of that which neither belongs to the seller, nor can belong to the buyer. The most unprofitable of investments. - Ambrose Bierce
O, that this too too solid flesh would melt, Thaw and resolve itself into a dew! Or that the Everlasting had not fix'd His canon 'gainst self-slaughter! O God! God! How weary, stale, flat, and unprofitable Seem to me all the uses of this world! - William Shakespeare
And let there be no purpose in friendship save the deepening of the spirit. For love that seeks aught but the disclosure of its own mystery is not love but a net cast forth: and only the unprofitable is caught. - Kahlil Gibran
Any business arrangement that is not profitable to the other person will in the end prove unprofitable for you. The bargain that yields mutual satisfaction is the only one that is apt to be repeated.