How do you figure that they can make up to .25 BTC each? I am not aware of any signature deals that pay that much, unless you are posting over the advertised maximum.
I guess he could be talking about the Bit-x signature campaign. They say you have a 99% chance of getting paid for the posts you make above the maximum.
That would involve people having to make 312.5 posts per month to make that much. Not only is 930 posts a lot to make each month (over three accounts), but to advertise that someone can earn a certain amount that amount would only be earned on a case by case basis is very misleading IMO