I'm looking at one of their massmail fliers right now...
Nobody is going to pay someone $15 to put a few staples in a 15-30 page booklet. No one. Not for work you can get done at any Staples or Office Depot copy-center for 1/30th the cost, or simply hire any number of minimum-wage workers- who can surely figure out how to staple more than three books each hour. And they're paying for all postage and envelopes?
Scammers use outrageous claims to sucker in the naive, and the desperate. Their pay is unrealistic. Their guarantee to pay you all your money back plus $30 if you're unhappy is insane. It is there to help make you feel more confident sending them money.
Rule of thumb - if a company sends you something completely unsolicited insisting that it is looking for complete strangers, because it wants to give them large amounts of money - but first you have to send money to them... they're criminals. Just that simple.