Learn English – How to properly define and use the phrase, “buy into”


I found this line while I was reading:

That commercial said that this product would help me lose weight in one week. I’m not buying into that idea.

While I somehow understood the meaning of the whole sentence by reading between the lines, I could not grasp the whole idea of the phrase when I isolated it from the rest of the sentence.

I tried to find decent definitions on the web but they could not properly give the proper use of this phrase (since there seemed to be different views on it). Could anyone please enlighten me on this topic? Thank you so much! :)

Best Answer

The example that Elliot Frisch gave was for the figurative use of "buy", not of the idiom "buy into".

Buy into (or buy in) has a more specific meaning: to agree to/ approve a {project/course of action}.
See definition (2) at http://idioms.thefreedictionary.com/buy+in

It is often used in businees contexts, where someone proposing a project must get management buy-in (noun) before starting the project.

This is still based on the literal sense of "buy", since the management is implicitly approving the expenditure of funds, as well as time and resources, on the project.

Sometime this is called blessing the project, on the analogy of a religious blessing rite. That is, a project can go forward once the "gods" in the executive suite have looked on it favorably, as something worthwhile.