You should persisted a little more.

She also said "have a nice day" very politely after a second or two

Next time, and actually always do the following.

"Let me get your number" whilst pulling your phone out, in your case by the passive way you reacted I gather it's stowed away in your Gucci purse.

I often give my phone to her because I usually have pussy juice soaked fingers and will often mistype or miss hear the girl.

Upon getting my phone back "Cool. I'll text you now so you have mine."

It's really that simple. Not really rocket science is it. Instead you kinda made a deal of it, but that's ok you now know better for next time;)

OMG a definitely IOI!! Now you can go tell your buds about the hot chick who said "have a nice day"...and once your elation wears down reflect on what could have been.

I'm not saying it like that lol I"m saying it like she was kinda not open to keeping the convo going even

"I can't" may mean several things such as she has a bf, is dating someone she likes, has a penis under her skirt, who knows doesn't matter really...

Not every girl who finds you "attractive" will date you, and yes, as one of the guys above mentioned persistence is good for polarizing the girl one way or other. It CAN be a very attractive quality if she feels something towards you to begin with as it demonstrates confidence and also women love to feel pursued by someone of 'value'. The difference between a guy she's attracted to and a guy she isn't attracted to with respect to persistence: attractive guy is more attractive, unattractive guy is 'creepy'.

Anyhow I get the sense the convo was just a bunch of fluff, be outright "hey you're cute too" vibe step up a bit, stick your neck out...often times women can tell when you're posturing and for a moment its 'cute' but after that its a turn-off. Go straight for the jugular.

I picked up an ex (a best friend of mine now) who worked at a Club Monaco (clothing store similar to Banana Republic) at a mall near where I'd lived. I went in tried a top on I had no interest in buying. The size was way too large, she came to ask if I'd needed help and I just straight up said "Look I didn't come in here for the clothes...I came in here because I think you're incredibly cute and had to say something". She blushed, I got her #, we ended up in a 7 year relationship, best I ever had to date:) And 8 years later we're solid as friends.

Why I am saying this? Take chances, ALWAYS, but beyond that BE BOLD. High risk=high reward.

I understand where you are coming from, but on the other hand It's not really my style to outright say she is cute. I tend to not give much in the early stages, in fact I never really like to compliment at all (until we are committed, or at least just give backhanded compliments).

I had a bit of a sexual tone but not too crazy. I don't think I was posturing much at all, I think the convo was more like:

Me: Hi how are you
Her: Hi how many? *smiles a bit looks down*
Me: Two, which side
Her: That one
Me: Oh good, don't want to confuse those *slight smile*
Her: How'd you do?
Me: Wonderful, *hands her tag* I don't usually give strange women my number
Her: hahaha

10 min later

Her: Back for more?
Me: Yup, now this color
Her: I'll hold on to this one for you
Me: All set
Her: How'd you make out?
Me: Good, now we have two winners
Her: Ok I'll take that, now can I have the number
Me: Give me yours first *smile*
Her: I can't *smiles* *takes the tag*
Her: Have a good rest of the day