I think the trick is to give them something interesting, fun and Trek. If the goal is to get them to play on a continuing basis, then you need to capture their interest, the way a good TV pilot captures your interest. But you have to give them what they want. If they want action, give them DS9/Dominion War. Or a TOS era war with the Klingons, or Enterprise era Romulan War. You could have them play Free Traders on the edge of Federation space, dodging and duping Star Fleet, and fighting the Orion Syndicate. You could set the adventure on a Star Fleet escort ship, taking on pirates and smugglers to safely deliver desperately needed medicine. The key is to hook them with the story. If the story is good enough, the setting will be irrelevant.
tmutant
Founder of the Evil Gamemasters Support Group. No, Really.