Philosecurity has a great interview [link] with Matt Knox, "a talented Ruby instructor and coder . . . about his early days designing and writing adware for Direct Revenue."

The whole thing is fun . . . here's a taste:

?: Let’s back up a second. Why did you write adware?

A: I was utterly and grindingly broke for a little while. I started working on SPAM filtering software. That work got noticed by [Direct Revenue], who hired me to analyze their distribution chain. For a little while, the site through which all their ads ran was something like top 20 in Alexa. Monstrous, really huge traffic. Maybe 4 or 5 months into my tenure there, a virus came out that was disabling some of the machines that we had adware on. I said, “I know enough C that I could kick the virus off the machines,” and I did. They said “Wow, that was really cool. Why don’t you do that again?” Then I started kicking off other viruses, and they said, “That’s pretty cool that you kicked all the viruses off. Why don’t you kick the competitors off, too?”

It was funny. It really showed me the power of gradualism. It’s hard to get people to do something bad all in one big jump, but if you can cut it up into small enough pieces, you can get people to do almost anything.

In case you are wondering, that's the very same Direct Revenue who faced a lawsuit from then-New York AG (now real estate developer) Eliot Spitzer.  Prof. Goldman has blogged a bit about that case, and you can access an amicus brief he and some others filed "on behalf of neither party" in that case [here] [pdf - the brief starts on page 5].  (Here's an earlier blog post from Prof. Goldman on the issues in that case.)
 
In any event, it was a fun/illuminating read.
 
More:  Professor Goldman in comments provides a link to the Direct Revenue decision in which the court squarely rejects the New York AG's arguments.  I should have included this link initially.  (I wasn't trying to set up a comparison between the case in the courts and what's conveyed in the interview.)