tanstafl 

There Ain't No Such Thing as A Free Lunch.

Very old slang, dating back to before ain't became a legitimate English contraction.

I means that a prospect is too good to be true(TGTBT), in that you are being offered something for nothing.

Nate: Your eMail says Bill Gates will give you $250 for each person you send this to that sends it to someone else.

Uncle Dick: TANSTAFL.

tanstafl by Ronin Catholic January 3, 2008

TANSTAAFL 

Acronym for: "There Ain't No Such Thing As A Free Lunch"

Accredited to author Robert A. Heinlein in his novel "The Moon is a Harsh Mistress"

TANSTAAFL is the golden rule.

TANSTAAFL by Depherios November 15, 2003

TANSTAAFL 

Abbreviation

A common shorthand for the colloquialism "There ain't no such things as a free lunch" implying that anything, as free as it may appear, has a real hidden cost.

(SMS)

Fred: WTF!? My stay was comped, but at checkout they charged me 4 the cable, phone, and internet!

Barney: TANSTAAFL

TANSTAAFL by Guesty Sueless May 31, 2010

tanstaafl 

There Ain't No Such Thing As A Free Lunch

tanstaafl by Flamin Homer May 31, 2003

TANSTAAFL 

T.here A.in't N.o S.uch T.hing A.s A. F.ree L.unch
Something advertised as being "free" will invariably have hidden costs.

Kid: Woah, why does Facebook have a whole bunch of Ads on their site all of a sudden?
Teacher: TANSTAAFL

TANSTAAFL by JBLuverxo<3 November 18, 2011

TINSTAFL 

An acronym for "There is no such thing as a free lunch."

"When in doubt, just remember TINSTAFL!"

TINSTAFL by neops August 13, 2005

TANSTAAFL 

There's always new shoes to appreciate, adore, fondle, love

I broke up with my girlfriend and TANSTAAFL

TANSTAAFL by TANSTAAFL Man December 10, 2012