A non-committal (on the surface) response to a statement the phrase user finds, unconventional, unacceptable, heretical or bizarre. The undercurrent or true meaning is often fuck you
, and the purpose is always to denigrate or dismiss what was said.
This phrase is often used in meetings and among members of 12-step groups, especially Alcoholics Anonymous, but appears to have wider usage (see entry in The Free Dictionary).
Usage is similar to Thank you for the flowers
Heretic speaking in AA: "I've found that I can stay sober without taking the steps, and I don't have to come to meetings every day, and I don't need a..."
AA meeting discussion leader: "Thank you for sharing. Who else has something to share?"