Global travellers expect easy and continuous network connectivity at reasonable cost, everywhere
They prefer to use their own mobile phone, contact lists and memory cards and avoid the hassle of using prepaid sim-cards, even if they have a dual-sim phone
They want to be able to share the network with their peers, families and friends
Roaming charges in Europe are expensive for foreigners, especially for those coming from outside EU
EU travelers may have lower roaming charges but may still have a cap on data usage and/or charges per MB used