Usually it's the chick who doesn't respond, but I can hypothetically imagine value in leaving her hanging. There are obviously different contingencies involved:

1. You created strong attraction in the initial interaction, but logistics didn't work, so you took the number instead. You're going back and forth over text, and although she says she wants to hang out, "she's busy with work."
Me: My friends and I were hanging out with some girls that we met on Friday night, and near the end of the night, one of them was begging me to get her blow...I was like "uhh I don't mess with that stuff." lol
Her: She probably judged you haha
Me: I don't care if she judged me, I wasn't that into her anyway. Definitely lost interest after she started begging for drugs haha
I'm glad you haven't asked me for drugs yet
Her: Was she as cute as me?
Me: Not even close. Actually, I couldn't help noticing that you're mind blowingly hot
Her: Well thank you bla bla bla
Me: You're welcome it's a matter of subjective taste, of course
Her: I'm glad I'm your taste then

Stop responding here, or keep flirting with her?

2. The opposite situation. Initial interaction is good, she's interested, but logistics don't work out, so I take her number. She responds to texts, but only after a few hours.
Her: I had fun last night! Thank you for driving me and my friends home.
Me: Haha you're so cute
.....quiet for a few hours
Her: Awe thank you

I think this one is a flake, she's more concerned with going out every night with her girls and sniffing coke than anything else. Keep texting, or go dark until next weekend?

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My #1 MONEY line to pull sets: https://www.youtube.com/watch?v=NkHjnZgCP18 (0:25)

Stop being "perfect." It's time to evolve.

Not everyone is sitting by their phones replying to every single incoming text they get; some are busy so I wouldn't read anything into delays.

Use texting to schedule meet ups. You have nice back and forths but you need to be closing.

That would be a good time to call her and see what she's up to... and if she'd like to get a drink.
As oceanx said, reasonable delays in responding are fine. People have lives... if she waits days to get back to you, then yeah - probably a safe bet that you're not at the top of her priority list.

On a side note, this girl is a coke-head? This is your target?

I only use text for meetups now. Lost too many girls from failed text game.

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My Boss Idols: Harvey Spector(Suits), Daniel Craig(007), Toretto(F&F)

what most new guys don't understand is that too much texting undermines value despite the great and clever text that makes up the actual content. Use text content, text length, text timing, and text response intervals to help you, don't allow them to work against each other