It makes the VIP subscription the ideal choice if you're planning to join a Kinship (Lord of the Rings Online's equivalent of a Guild). In chat they can't send more than one tell every five seconds and while they can bid and buy items in auction houses, they can't post any items themselves. It also removes all chat, mail and auction limitations: free-to-play players have limits on how often mail can be sent, and can't send gold and bound items through the system. The sub costs about £10 a month and gives you more character slots, storage space and 500 Turbine points a month to spend. If you prefer, you can still pay a monthly subscription to become a VIP player. Buying an item from the store also automatically upgrades your account to Premium, giving you more character slots on each server and increasing the limit on the amount of gold you can carry. It is possible to play through the high level areas for the story missions alone, grinding the wildlife to gain levels between each quest, but it's a miserable alternative, and if you're invested enough to reach level 20, five or six quid every now and then feels worthwhile.
Once a quest pack has been purchased, the areas are available to explore at your leisure, removing the pressure to play enough each month to justify the subscription cost.
While this initially seemed unfair, I came to prefer it to the traditional monthly subscription approach of most MMOs.