I agree with being cordial. However, what if she wants small talk? Clearly she isn't interested. At this point she could be doing it for an ego boost. Would you engage with small talk or just say hello and carry on shopping, i.e. don't get sidetracked from your purpose there. Furthermore, would you actively engage with her if she didn't with you? By that I mean, would you go out of your way to say hey to her first, or wait for her to initiate the niceties?Yes, live your life without worrying about it. It's not a strategy but just a state of mind (and good time management). Just because she turned you down is no reason to shun her. If she says hi again some time, say hi back, if you want. It's up to you to decide what's a waste of your time though.