When you visit the Amway Global blog, they have a section I believe called "by the numbers". When you click it, it takes you to "Thisbiznow" and shows the average income of "active" IBOs to be $115 a month - and that's after disregarding about 1/3 of the IBO sales force as they are not "active". I believe that this figure is based on a 2001 survey done by the corporation (And Amway supporters complain and bemoan critics for not having current information).
One of the things I often hear from Amway supporters is a comparison of Amway and franchises. (McDonalds in particular). First of all, unless I am mistaken, Amway is not a franchisor, and their salesforce (IBOs) are not franchise owners. This is simply a trick used by some lines of sponsorship to make you feel nice and important (I guess). So there is no valid comparison between an IBO and McDonalds. If Amway were franchising businesses, I am sure they would tell you so.
But let's look at one very telling comparison between Amway IBOs and McDonalds. In Hawaii, the minimum wage is $7.25 an hour. If someone were employed at McDonald's for $7.25 per hour, and they worked 5 hours per week, or 20 hours in a month, their gross income would be $145.00! That's more than 30% more than an average IBO receives from the Amway opportunity! For you average IBOs out there - want a 30% raise? Get a 5 hour per week job at McDonalds! Go Big Mac!