Sorry for the late reply, but I got the urge to visit YouTube to see the Ballet Folklorico do the Jarabe Tapatío... Which then got me started watching flash mobs doing unseemly things to innocent bystanders.
I think the JWs have two immediate strikes against, one of which is immediately draws a hostile government response in a new country: they preach against national unity. No observance of nationalist holidays or ideals and they try very hard to convert people to follow them in this behavior.
The Mormon church has more sophisticated public relations. The church meets with the leaders of countries. Butters them up with gifts and provides aid in various ways. It can be in the form of agricultural experts who help the local farmers grow food more efficiently. It can be in the form of medical missionaries. Relief in the case of a disaster.
Also the Article of Faith that says We believe in obeying the laws and leaders of the land does not hurt.
The Mormon Church is the perfect religious embodiment of a multinational corporation. I can't think of another religious denomination that is even a close second. Catholics have the international hierarchy, but the lay members are not trained to think, dress and act like corporate cogs.
A "good" Mormon is amoral, materialistic, and follows orders.
One reason that mormons are more popular is because the church is willing to pay faith money to bribe governments to let them in. Another thing that the church has going is that they encourage members to pay taxes after they have paid their tithing. lol