You are always connected and always contactable- With an international roaming phone you are always connected and always contactable. You can make a call back home without worrying about cost or finding a landline and it is also easy for people back home to easily contact you because they know exactly which number to call you on. An international SIM card mans that people can call you knowing that they will be able to reach you. In the past people have considered getting prepaid SIM cards from each country they travel to but this is not convenient. An international SIM card solves these contactability problems.
Helps improve your cash flow on your travels- Roaming SIM cards are generally prepaid which means that when travelling you can control your costs. You will be aware about the money that you are spending at all times as you will be paying as you go to make your calls. Postpaid calls with your home mobile phone can lead to huge unexpected bills. This may not cause cash flow problems whilst you travel but it can cause major issues when you get home.
Huge savings - One of the best reasons for you to look at an international roaming SIM card is because of the cost savings. In some countries you can save up to 90% and some SIM cards also allow for free incoming calls. You would never get this opportunity for your own home mobile phone.
The biggest piece of advice is to make sure that you don't take your home mobile phone with you overseas. Use an International SIM to maintain contact with people back home whilst also saving a fortune and improving your cash flow.