"More is not better, only better is better," Plepler told CNBC's "Power Lunch" on Tuesday. "It is very hard to create outstanding content, and we think we have a good record of doing that very very well. We're not trying to create the most, we're trying to create excellence across our categories -- and we have more than the resources necessary to do that."
As more companies like Apple and Facebook step up investments in content, there's increased competition for show and movie rights. HBO is banking on its reputation for quality programming to stand out, Plepler said. The company spent $2 billion on content last year.
"There's a surfeit of content out there," he said. "Some of it is good. Some of it is mediocre. Some is not so good. I think what our brand reflects and has reflected is that when you come inside HBO you will see something that stands for quality."
Still, Plepler acknowledged that rights are getting more expensive. He also said that original programming isn't the only draw for HBO customers. Movies from the four major Hollywood studios make up 73 percent of all its viewing across TV and its platforms.
"We're going to spend what we need to spend to spend to make sure we are creating outstanding programming, curating in a way that our brand continues to stand for excellence," Plepler said.