[kia345]

Create a small "trial server" that any trial can play for free for as long as it takes to get them to buy an account. Give it like, 2 events a week, few NPCs, and little to actually do, like limited spars (each person gets 5 rounds a day), restricted pk'ing (very few pk levels), and lots of ways to separate players (5 islands, like GK, with no way to get between them; you log on, and are confined to your island; and having unchangeable nicknames and guildtags). Constantly have the PRs, the main staff team, telling people how awesome upgrading is, and have high quality ingame billboards depicting servers they could be playing. It could be an alternate for of advertising playerworlds too!