Expressão: Put your money where your mouth is

Eu gostaria de saber o que significa essa expressão " Put your money where your mouth is " eu vi ela em duas musicas e não entendi o significado. Até pq nos sites de tradução de musica eles colocaram isso no pé da letra e ficou bem estranho.

A 1ª musica é do JET - Put your money where your mouth is

he's a loaded gun
In my shaking hands
Am I in hell, or the promised land, yeah

(Whats your name)
So I tell you my name when I'm on your skin
(You can be)
You can be the queen, and I'll be the king
(I'll get born)
Now I'm gonna echo but never again, not for anyone, anyone

She said
Show me yours, (Show you what I got yeah)
I'll show you mine (Will you tell me what you need)
Show me yours, (So put your money where your mouth is)
I'll show you mine (Scream...)

And the beat goes on
She knows nothin' is wrong
She goes down, like a setting sun, ow

(Whats your name)
If I tell you my name you gotta let me in
(You can be)
You can be the sinner, I'll be the sin
(I will take)
I'll take what I want, and it's easy to see, I got everything, everything

a 2ª da Katy Perry - Waking up in Vegas
Refrão
" Shut up and put your money where your mouth is
That's what you get for waking up in Vegas
Get up and shake the glitter off your clothes, now
That's what you get for waking up in Vegas..."