Nelson initially started WeRateDogs on Twitter just to brighten up people's feeds. But the account gained thousands of followers overnight, and that figure has kept climbing ever since. Currently, it stands at a whopping 9 million. Nelson was even able to turn the account into a business, selling merchandise and posting branded content.

"[I] got addicted to trying to make people laugh in that constrained character space," he told CNBC Make It. At that time, a tweet could contain only 140 characters.

As Nelson tweeted, he noticed that "every time I would post a picture of my dog or any content that had to do with dogs, it would do much better than my other content... That signaled that the internet loves dogs just as much as I did."

Nelson launched WeRateDogs back in November 2015, when he was a college freshman at Campbell University in North Carolina. In fact, he released the account's first post from a local Applebee's, featuring the pup of the friend he was having dinner with.

By that night, Nelson received hundreds of messages from dog owners asking for their pups to be featured. At first, he also promoted WeRateDogs from his personal Twitter account, which had about 10,000 followers at the time but by the end of that week, it already passed him in followers.

Nelson became overwhelmed with juggling college, a job at a golf course, and his social media newborn pretty quickly. However, instead of selling his side hustle, he decided to drop out of college before his junior year and moved in with his parents in West Virginia to focus on WeRateDogs full-time.

Fortunately for Nelson, his parents and close friends were very supportive of this bold decision and believed he could continue growing WeRateDogs. His dad, an executive director of a law firm in Charleston, even helped Nelson manage the business' growth once he started raking in significant revenue.

But the project is more than just smiles and awws. Nelson is also focused on raising money for dogs in need, posting links to crowdfunding campaigns each Friday. In 2020, for example, WeRateDogs helped raise $1.3 million!

In addition to encouraging his millions of online followers to contribute to these noble causes, Nelson also regularly donates to such campaigns.

"Since we only post one or two per week to the audience but are sent hundreds of others, we typically pick another one, in which either I will personally donate or WeRateDogs will donate as an organization," he explained.

The weekly tradition started in 2016 after Nelson realized a dog he featured needed a wheelchair. The dog's owner asked for about $500, but after sharing the fundraiser, $700 was raised in just 45 minutes.

"It was very clear that my audience was looking for a way to give back," Nelson said. And they still are! Consider this: each campaign that appeared on WeRateDogs has been fully funded within an hour of being posted.

Nelson hopes to continue to share these campaigns with his audience and raise more money, as he found that many pet owners struggle to cover medical expenses, especially when most of them do not have pet insurance.

“Part of the reason [WeRateDogs] has been so successful is because our audience trusts us with the curation of these stories, and now, our audience trusts me," Nelson said. "So, that consistency of posting every Friday and getting our audience used to it has really helped it become what it is like now."