Religion and cult aren't that much different but there are some.
How does a group recruit? JW contact people and offer to study the bible, but they study their interpretation with the help of the bible. They start off with ideas that seem logical and may be true as per bible. As the student progresses in his "study" he is more prone to accept the ideas that are fed to him later in WTS 1914, 144000 and others. The student is encouraged to go to meetings and is love bombed and encouraged to return to and enjoy more talks and so forth. People seem friendly. As the student progresses and associates with JWs, he (the student) imagines he is gaining friends and is accepting their teachings directly or subconsciously that the world is evil and only people that will survive God's wrath are faithful JWs. Baptism is only a logical step. Once the individual gets baptised which by then he should have abandoned most of his "worldly" associates - the worldly friends aren't your friends just associates - that's what I was told many moons ago :) Anyways by that time he's surrounded by new "friends". He has never seen past teachings and never researched the history or the orgnization. Anything that is said against the JW individuals or the organization is from Satan or the opposers so he shouldn't believe these. By this time the individual in well along being programmed to stay away from old friends, not associate with outsiders as much as possible, not question God's organization and is bombarded with same propaganda at all meetings on regular basis.
If the individual now somehow discovers something odd about the group, either old docrines, or finds some skeletons in the closet he seems to find himself at odds with the rest of the group. If he brings up his concerns they are either dismissed as lies, or half truths or old light as the group has been enlightened since then. Now, if the individual continues with questions he may be viewed as a trouble maker who is causing divisions and the elders will have a chat with him. If there is no improvement the elders may call him and talk with him in a court style where he will be questioned as to his loyalty to the organization. If the elders don't like his tone, or his reasoning and can prevent him from seeing their way the individual is kicked out. Upon this action, majority IF NOT ALL of his JW friends and by this time maybe even his family may began to shun him. So not only did the individual leave behind his old friends he is not an outsider to all the people he come to know and make friends with. Some won't even acknowledge him when they pass him by even though they don't know the reason but that he's no longer part of them.
How many religions do this? Does Catholic Church? Do Protestant Churches? You may see this sort of behavior out of high control groups and cult but very few groups seperate their members from the real world. So WTS may not be a cult on the same level as Charles Manson's group but they are a cult nonestheless. On many levels they are dengerous to the members and their kids.