1. QuickIM is VERY data bandwidth friendly. This is because as opposed to some other messengers (free or paid) that are proxy based, QuickIM uses direct socket method to connect to instant messaging servers, and doesn't need to poll the server for new information every few seconds, instead it sends/receives data only when there is truly a message to send/receive (once an hour?). The difference in GPRS data cost is of course HUGE!
2. it connects directly to the instant messaging network instead of through a third party vendor own gateway as it is with most other solutions. The positive point being your chat messages won't be intercepted by a third party gateway with potential confidentiality issues (important if what you say may contain sensitive information).
3. The pricing of QuickIM is one time fee as opposed to annual subscription fee of some other paid solutions. So it may be more expensive than a free solution, but its cost is limited compared to other paid solutions if you do care about not letting third parties read your messages.