I had this secret. I robbed banks in my spare time.

Lives less ordinary from the BBC World Service.

This is not a good thing to do because police are after you.

Find out more at the end of this podcast.

Hi there. Welcome to Business Daily from the BBC. My name's Ed Butler. Today, the global ad racket.

Our criminals are ripping off advertising firms to the tunes of billions of dollars every year.

There's entire botnets that are dedicated to click fraud. It's a business. They have a full-blown industry. It's a money-making industry.

And we hear allegations from one fraud detection expert who reckons the entire digital ad industry

is itself part of the problem. Marketers are starting to realize that their spending is not

actually producing the results that they thought it was, they're finally willing to ask.

Am I getting what I paid for?

And most of them are finding out that they're not.

Getting into the weeds of the digital ad market, business daily from the BBC.

I'm Andrew Lissimore, the CEO of a Canadian company that sells really high-end headphones.

We were growing this company, and part of growing a primarily digital retail company,

is advertising, is reaching our customers across a number of websites and web properties.

What Andrew was trying here is pretty standard for small companies in the digital age,

using so-called programmatic or targeted advertising via the internet to spread the word about his

great new product. The way it's meant to work is that these pop-up ads appear only in front of the

right type of people who'd like to buy what he's selling. He pays when someone clicks on the ad.

He'd hired an ad tech firm to organize this, but then things started to get weird.

Our ads were showing up on a lot of Android games. Android games are a very unlikely

...