If you spend any time with email, you've probably received an occasional chain letter, in spite of any spam filter settings meant to protect against that sort of thing. The spam promising a financial windfall from little-known African banks is well known, as are the announcements of lottery winnings for contests in Europe that you don't remember having entered. There are prayer chain letters, too, some of which are started in support of American military personnel.
An acquaintance forwarded a "Prayer of Saint Therese" to me yesterday. Curiously enough, it doesn't sound like anything a pious nineteenth-century French woman would actually have written. But it did spark a few thoughts on chain prayers that you might find instructive or entertaining.