For a while now my store has hosted the official Dungeons & Dragons Encounters. Each week two volunteers make time to come down and do an excellent job of running two separate tables full of players. They participate in high fantasy skirmishes full of monsters, traps and grand treasures. They all seem to have a good time of it to boot.
The core concept is sound, but sometimes I feel like there's something missing. While the Encounters are an excellent way to introduce new players to a fun hobby, it's still only a stepping stone. The role of any good RPG is to act as a cooperative form of story-telling. So now on Thursday nights I make an effort to run some of the less known games on our shelves. These games are run in a much more narrative style. The rules come second, and the story and characterization comes first.
The store benefits as well. Sales for 4th edition have been down. It seems most of our encounter players have become comfortable with their play-style and the books they already own. Rotating the Thursday night game every couple of months not only keeps my players and I engaged, but it provides a built-in forum to introduce the players to new products they wouldn't have picked up on their own. Using the narrative style is an excellent way of shining a new light on old stock, or giving mechanics-heavy games a twist for more casual players. For example, allowing the players to dive right into the world of Shadowrun without over-loading them with the minutiae of it's mechanics made believers of even the most casual player.
Letting players experience different genres and modes of play are all important factors when it comes to the health of the role-playing section, and the retail space overall. This concept can be translated to other games as well. You can restrict the next 40k event to a more casual vehicles-only battle, or add narrative benefits to a dungeon crawl game like Tomb. These are excellent examples of twisting things just enough to make them interesting for new players as well as returning veterans.