buy into your idea or product

[keannu]

Does "buy into" mean "trust or believe" or "invest in something"?

ex)....Even if you have a good idea and the technical expertise to create the product, you will still need the services of an accountant, lawyer, banker, or distributor to make your product successful. All of these people need to buy into your idea or product. You not only need a good idea, but also the ability to communicate your vision and the ability to produce and sell the product with the help of investment.

[Rover_KE]

Does "buy into" mean "trust or believe" or "invest in something"?

Yes. They need to be convinced of the viability and potential profitablity of the product.

Rover