Then there is usually a website address (and sometimes even a phone number) as well.
If this person simply has their domain name forwarded to an affiliate link of a "make money online" product they could be making some good money from the traffic they are pulling from OFFLINE leads/customers...
You could take it further and have them go to a squeeze page that would allow you to collect their email address and then you could build a list!
This could probably be done in more niches than the "make money from home/online" niche.
Think about it... You could leave cards or fliers near the cash registers in any convenience store that will allow you to. You could promote weight loss products, health & fitness products, self improvement, auto related products, real estate & foreclosure eBooks, etc, etc.
Just make sure to have your website printed clearly on the card/flier and have it forwarded directly to an affiliate link or to your own squeeze page, landing page, etc.
Of course this is nothing NEW, but how many extra affiliate sales or leads can you bring in by promoting them OFFLINE?