A 2013 Federal Trade Commission report cited complaints that totaled 5 million in losses to romance scams alone, according to the Wall Street Journal.
Still, these criminals must stay a step ahead of their victims.
But, these Internet criminals are not working alone.
Vendors also list guides on how to commit other illegal activities.
In August, a British man was sent to jail after defrauding two women of over £300,000 ($455,300) through online dating sites.
But there's a type of dating site scam that's far trickier to spot, and the people who operate it claim to be making thousands of dollars every month fooling vulnerable men.
Business Insider obtained a PDF guide that is sold online for just £2.59.
This is after a 14 hour flight and did not sit well with me.