I have been using this method for over a year now. It has been successful, and I don't see any way it can get saturated, so I thought I'd share. I'm sure I'm not the first to think of this - but I've never seen it anywhere. My apologies if its already posted. In very simple terms, I purchase stickers printed with a small message, and affix them to currency. I spend the money, and over time, people see my message, visit my site, and I earn CPA commissions. Here are some questions I thought you might have... Is this legal? I'm not a lawyer. Having said that, I did contact a lawyer, and his opinion was that the law makes it illegal to alter currency for fraudulent purposes. That is to say, if you ruin money, or alter it, etc - as long as the changes are not being done in an effort to defraud, it's okay. A great example would be penny machines, where you can turn a penny into a flat souvenir. These exist everywhere, so a person could assume it's legal. Also, if you have ever seen the website "where's george" you'll see that for over a decade people have been writing and stamping money - and the site still exists. So if it's legal, why use stickers instead of a stamp? Mostly because I was still nervous! So I ordered stickers from a few online companies to sample. To be even more careful, I ordered "low adhesive" stickers, so they could easily be removed without damaging the money. Tell me more about the stickers. They are 1.5 inches by 3 inches and contain 3 lines of text. 2 explaining the offer, and a website. They are bright colors. And again, they are low adhesive. Where do you place them? I place the sticker on the back of the bill, on the right side. I have found it easier to spend when the sticker is on the back (less people notice it immediately.) That means its more likely to get into the system and get viewed by more folks. Where do you spend them? Everywhere. I spend them anywhere you'd normally spend cash - except vending machines. I have yet to find a vending machine that accepts a bill with one of my stickers. Do people remove the stickers? Yes. About 20% of the time people rip them off as soon as they see it. I'm sure that holds true as the money gets spent and re-spent. On one hand that's depressing. On the other hand, how much advertising gets viewed, then passed on to be viewed again, etc? How do you track your efforts? Each time I order stickers, I get a new domain. Then I know those 1000 stickers can be tracked for my message as well as how long they have been in the system. Is this consistent income? Yes, very consistent, but completely unpredictable. I earn income very consistently, but I can have 10 hits today and none for 3 weeks. So while I have made good income over the long term, this is not a fast, or predictable income. I have had hits and sales within days of spending money, and I have also had hits and sales 10 months later. That part is pretty cool. How much can you make? Like all CPA, it depends on your offer and traffic. The average 1000 stickers cost about $100, and generate about $900 in income. My 3 offers range from $45 to $150 each. Seems like the stickers are affordable, but all that money would be expensive. Well, I started by just putting stickers on money I spend already, so the cost was just stickers. Then I wanted to try and get more out there, so I would go buy $1000 worth of stuff at a store in 3-4 transactions. Then return them. The cost was my time, but I spent no real money except for cost of stickers. Other ideas to scale this? Not really, I have tried getting friends who work at stores, or drive cabs. That helps. But in the end, it would be great to figure out how to "spend" 10,000 a day, and watch it generate long term cash. Message me if you have an idea. Which bills are best? In general terms, the larger the bill, the longer it will stay alive. So $100 bills stay alive for about 10 years before being shredded. $1 bills last about 2 years. I like to try and pick bills based on the offer - so for example, I love using $1 bills for $1 trials. Any issues with affiliate networks? Nope, and I have been clear on my method. If you are concerned, try promoting your own product. Hope this helps someone make a little extra cash!