A good number of employees is enough to handle your customer load. More important: having employees that understand and are enthusiastic about the product they're selling.
Right on OBDave
Not sure about recommendations from a business standpoint. But from a customers point of view, i have been to a few local places, mainly to try different juice manufacturers. There is only one, from a handful around me, that I will go to from now on. Mainly because they are VERY knowledgeable and can talk to you from a newbie, all the way to the I can build anything level. I by all means don't know alot, however I am not new to vaping. But they talk to you on your level and make you feel welcome. When I very first started, they sold me on what I was in the market for, not what was going to make them the most profit. Since then, I have went there for all of my needs except one. I bought a mod off of the internet, and they told me to bring it to them if I ever had issues with it.
I was in a different shop trying out juices near me when a guy who wanted to quit smoking cigarettes, stopped in & asked what he should start on & they recommended mods that I personally am not even comfortable working with. Another store had no idea what half of the mods or RDA's we were inquiring about even were. And most importantly, you have to let people try juices that your selling.
IMO, passion, knowledge and friendliness are going to make your business. Even if your prices aren't the lowest, you're customers will find you. I can tell which one of my local shops are going to last, and which ones will have a for rent sign up within the next few months.