Craig Watts has spent the better part of three decades trying to bring attention to the inequities between major agricultural companies and farmers like himself.

It's a battle that suddenly changed a few months ago.

"If you've got a problem and you want it fixed, call John Oliver," he said. "That's my theory now."

Watts was featured in a segment in May on Oliver's HBO show, "Last Week Tonight," that illustrated how the companies most associated with chicken in the U.S. take advantage of farmers. Since then, things haven't been quite the same.

"In 18 minutes, he did what we've been trying for 30 years to do and that is just reach a general, broader audience. The story that he told, I cannot tell you how hard that is to tell to someone that is not really familiar with it."

In about two years, Oliver has gone from Daily Show correspondent to the conscience of America, instigating on behalf of people in the trenches that are fighting the good fight. His show has touched on a wide variety of issues, from relatively well-known topics like LGBT discrimination and the U.S. government's use of torture to more arcane topics like TV televangelists and and food waste.

His segments carry weight, often going on for more than 15 minutes and pulling no punches in expletive-laden rants. And when he talks, people don't just listen. They spread the message far and wide.

"It has a huge effect," said Edwina Rogers, CEO of the Center for Prison Reform. "Now every social justice cause has hopes of getting covered in his show."

Plenty in the media are willing to take on tough subjects, but none are creating the type of wake left by the H.M.S Oliver. The ripple effects of Oliver's segments can be seen every day on the Internet, where digital media sites have made something of a Monday routine out of posting his segments, which HBO releases for free on YouTube. The practice — part of the online playbook written primarily by Oliver's alma mater, the Daily Show — became so widespread that The Awl began tracking it in their "John Oliver Sweepstakes."

A study by Internet audience tracking company Parse.ly found that Oliver's segments routinely change the amount of attention paid to the topics he addresses, even after the buzz around the segments themselves dies down.

The chart below shows online traffic for pages about contract farming before and after Oliver's segment.

Oliver's success online comes despite somewhat meager ratings. He's regularly beaten by regular basic cable shows as well as other HBO programs.

But what HBO provides is the pulpit, allowing Oliver to go after just about any topic he pleases at length. The Internet is the megaphone.

Scott Edwards, co-director of the Food & Water Justice Project, said that the segment on contract farming had reached far and wide, putting the topic in front of a new audience.

"It made a big splash not just because it was on John Oliver's show but because then the non-profit community picked up on it. The media community picked up on it, tweeted about it, put it on Facebook," he said.

HBO declined to make Oliver or anyone from Last Week Tonight available for this article.

Jon Stewart and John Oliver talk politics during The Daily Show's August 30, 2012 episode. Image: Brian Cahn/ZUMA Press/Corbis

It might be easy to dismiss Oliver's impact as a fleeting traffic grab by digital media sites — and maybe on some level it is — but he's having a real impact on the issues. His rant about "cable company fuckery" — more commonly known as net neutrality — stands as one of his earliest online hits. It also caused a deluge of comments to the website of the Federal Communications Commission thanks to his plea for trolls to direct their awfulness at the regulator.

The FCC went on to impose the strongest net neutrality rules to date.

Corynne McSherry, legal director at the Electronic Frontier Foundation, said that Oliver's net neutrality segment gave an important boost to the people who had already been working on the issue, in part because he made a strong call to action.

"He not only informs people, he often really lets folks know that if you care about this, here's where to go, here's what to do," she said. "It's very hard to get people to get excited about net neutrality because everyone just starts falling asleep immediately. I think John Oliver's genius is to take stuff like that and help people understand why it's important."

Even when Oliver tackles problems that are relatively common, he brings a fresh perspective to new audiences.

Prison reform has been receiving broad and bipartisan support, including from President Barack Obama and Congressman John Boehner, the speaker of the house. But when Oliver did a puppet-filled segment on the topic, he brought a serious slant to a problem that is usually the subject of jokes — prison rape.

Jeremy Haile, federal advocacy counsel for the Sentencing Project, which advocates for prison reform, said that Oliver's comments are rare and much needed.

"When he said that about prison rape, it was one of the more high profile times we've ever heard anyone say, 'that's not funny,' and now thats rippling out into presidential speeches," Haile said.

Oliver isn't just attracting attention. He's also starting to make an impact in the halls of power. Marcy Kaptur, a congresswoman from Ohio, has been working on legislation concerning the contract chicken farming industry. She recently notched a victory on that front, landing some protections for farmers in a recent appropriations bill.

Chellie Pingree, a congresswoman from Maine, said that Oliver's segment on the subject had helped spur support that resulted in legislative action.

Kaptur, she added, was quick to think of Oliver.

"[Kaptur] said, 'John Oliver, he gets a gold star,'" Pingree said.