First of all, this service is not for recharging your Dingtone account. You use it to recharge a prepaid mobile phone that could be yours or anybody's (your family or friends) in any countries.
Say, you have love ones in abroad. You use this service to pay phone bills for them.
If you use a prepaid mobile phone, you can use this service to add cell minutes. No need to run into a store to purchase a prepaid card.
When you travel in overseas, you may purchase a prepaid mobile phone service in the local country. you can use this service to add cell minutes. Find a local store is not easy when you run out of cell minutes.