Selling cards to a mainstream audience (and hers will have been more mainstream than, say, Gary) will have been a challenge. This is, I would guess, especially true when applying for cards which have a transferable currency - getting people who fly AA to get an AA card is a big sell, getting mainstream readers to get an odd card which converts into airline miles (so two currencies you don't understand) is even harder.
The pitching of the site also means that hard-core people who do apply for 6 cards in a day and may spread around the love would not be reading.