In the 80's there was a Boulder Sound Gallery in downtown Denver. As I worked downtown I'd pop in about once a week to see what was new or just shoot the breeze. I never gave them the "someday" line. I never monopolized their time and when there were other customers, I'd just nod or wave and stay out of the way.
It didn't take long until they were comfortable with me and moreso when I did start buying things. (I had a young family and money was tight.) One day I went in to buy some Monster Cable and connectors to make my own. They asked if I'd be interested in a barter: I'd make cables for their listening room and in return, I'd get mine for free. Win-win!
Eventually I bought my Acoustat 1+1s and an ARC SP3-A that had come in on trade.
My point is, there's a right way and wrong way to hang out in an audio store or any business for that matter. Don't be a dick and you should be okay. 