Competition between religious groups has always been keen, perhaps never more so than today. Studies have shown that many long-established mainstream denominations have lost huge numbers of members since the turn of the century, and the Roman Catholic church is experiencing such a critical shortage of priests that it has been forced to close some of its parishes. The common factor among these denominations is that they do very little proselytizing. On the other hand, churches which actively proselytize are experiencing a high rate of growth; the methods may include door-to-door soliciting, billboards, television and print advertising, and may also include free bibles or other items. By actively and aggressively recruiting, these groups (to include the "megachurches" are winning the competition for members and contributions.