The unlimited trial is a three edged sword

The first edge is that it gets people into the newbie areas, I'm not sure how sparsely populated their newbie areas are but I know I started a new char in WoW quite some time ago and it was so depressing I was like the only person there, so it at the very least fills the psychological aspect that assures new players the game is popular and full of interesting people even if they are "ten cappers"

The second edge is that it does give people a wonderful opportunity to explore the world, kick the tires and what have you. Run around get their friends to try it out and not worry about their trial expiring before their friend gets around to trying it, which is nice.

The third edge is simply that it prevents the people who would and could and otherwise do start a ten day trial and power themselves to the levelcap, I'm not sure how easy it is to level in Warhammer at the moment as I have never tried it but I have played many games where if you know what to do you can hit the level cap in under a week.