Threads a bit old but I'd like to ad some experiences in here.
I also have worked at many pet stores, mainly fish oriented. The worst thing someone could do to a browser is either ignore them, or just say hi. Most browsers, in my experience, are just shy and afraid to ask for help or ask questions.
I greet them with a friendly "Hello, how are you doing today?". It gets them talking. Normally followed by "My name is *insert name*, is there anything I can do to help you?" or something of that sort. 9 times out of 10, I get a question as a response from the customer. More often than not, I sell something. I just try not to be like some employees at larger stores that swarm on someone and always peaking around the corner at them, that's annoying and a good way to bust a sale. Whether it be a $0.59 air stone or a $1000 tank setup, I may have just made a customer for many years to come.
Now it doesn't always work and that is expected. But for the most part I think a friendly attitude and showing concern for the customer will get you a lot of future business.
Great idea with the hamsters. I've seen similar things done with toads, rabbits, extra aquariums, etc. It really gets people in the hobby. If it costs you $2-$5 to get a customer that spends that amount each week, seems worth it to me!