Unfortunately, this mastery conundrum is not really at the core of the business. Our core job is to cater primarily to hobbyist beginners. Just yesterday I helped a father select a role-playing game for him and his two sons, assisted a customer with choosing primer and teaching basic dry brush technique, recommended a Magic intro pack to a boy who was starting out, and suggested a board game gift for someones sister. This is really what our store is about, but strangely, we're not as prepared as we should be for this type of assistance. When it happens, we have to shift gears and think deeply about what we're actually being asked. It's not as natural a question as it should be.
The issue is we're primarily in contact with experienced gamers, in fact, the most experienced gamers, as they come in most often and spend the most money, usually about once a week. We talk with them constantly about new releases, issues they have with their games (oh god do we discuss this), and cutting edge stuff they want. They reward our experience and knowledge by spending the most money of all customers. Customer interactions of this type are probably around 80-90% of my interaction (and can actually scare away some of the neophytes). However, despite the many questions and the money they spend, these guys don't really need us.
In fact, there are quite a few experienced gamers that have "transcended" our store entirely, as they no longer are getting the value we once provided. Anyone who is deeply serious about their game will likely have more detailed knowledge than anyone on staff and unless they need a place to play, we don't provide much value for them. I figure we stock about half of what they want, the other half being obscure and unique enough that we often can't even get it.
As store owners and employees, we're conditioned daily through customer interactions to chase these transcendent customers, to want them in the store, to adjust the business process in every way to make it more about them, and less about the beginner who walks in the door. For example, our "new arrivals" sections have been changed to at least contain 30 days of new product. For a while we were looking at a 7-day turn around, based on those high frequency customers (beginners are oblivious to this). That beginner is the core of our business, but we forget, both because of the interaction frequency and the Pavlovian effect of big spending regulars.
As gamers ourselves, we want very much to cater to that transcendent gamer, mostly because they are somewhat like us in their desire for that game just over the hill or that ultimate character build. We (often mistakenly) seek out the fringe products that we know we want and that will satisfy the transcendent gamer, but what we should really be doing is focusing on the beginner.
Beginners need more signs (even if we don't think they read them). We need to work on our sales pitch for board games based on customer needs. For example, name three games a beginner can play with seven people. We need to have more game demos, which we rarely do, to be honest. We need to make sure our desire for personal mastery doesn't make us sound arrogant, condescending, or dismissive, a trap that many store owners fall into. In other words, we need to fight our daily conditioning and focus on the folks who will grow our hobby, our business.