Like Simon and keyser soze, I grew up with the impression that spare money went to the WBTS and Armageddon was going to sort out everything else. 'The poor will always be with you' thing. No real 'official' policy, just the internal culture pushing things in a certain direction. They push things like giving to WBTS means 'charity' in the normal sense of the word happens.
eg "How Can We Help to Meet the Needs of Others" (13 November, Watchtower)
In the face of natural and man-made disasters, we do not tell needy brothers and sisters to “keep warm and well fed.” (Jas. 2:15, 16) Instead, we seek to provide for their physical needs. Similarly, after receiving warning of a coming famine in the first century, “the disciples determined, each of them according as anyone could afford it, to send a relief ministration to the brothers dwelling in Judea.”—Acts 11:28-30.
As Jehovah’s servants, we are eager to help needy individuals in a material way. However, people also have a spiritual need. (Matt. 5:3) To help them become aware of that need and take steps to satisfy it, Jesus commissioned his followers to make disciples. (Matt. 28:19, 20) We individually devote much of our time, energy, and resources to carrying out that commission. As an organization, we use some donated funds to provide material help, but donations are used chiefly to promote Kingdom interests and spread the good news. We thus show our love for God and for our neighbors.—Matt. 22:37-39.
Those who support the worldwide work of Jehovah’s Witnesses can be sure that their donations are used properly and effectively. Are you in a position to help bring relief to your brothers in need? Do you desire to support the disciple-making work? If so, “do not hold back good from those to whom it is owing, when it happens to be in the power of your hand to do it.”—Prov. 3:27.
WBTS is a one stop charity shop according to Brooklyn.