Richard Plepler has a message for Brian Roberts: Don’t turn your back on his streaming service.

The HBO CEO called out his Comcast counterpart and multiple other leading U.S. pay-TV distributors who don’t offer HBO Now with their broadband products as digital giants like Apple and Google have over the past nine months.

“If you’re Brian (Roberts) and you have 6 million broadband subs, why would you not bundle HBO and share that revenue with us? Why would you give up that real estate and not be paid for it? I don’t understand it,” he lamented Tuesday evening in a keynote Q&A at the WSJD Live event in Laguna Beach, Calif.

Plepler repeatedly criticized distributors who he complained were leaving money on the table by not using HBO Now to help drive value to their own broadband access. “Some of our partners are not as skilled at that, and I think that’s myopic on their part,” he said.

HBO has managed to secure two deals with traditional distributors — Cablevision and Verizon — for HBO Now. However, Comcast, along with the potentially combining Charter and Time Warner Cable, do not offer the service. Neither do satcaster DirecTV or its own merger partner, AT&T.

Plepler dismissed the notion that HBO Now would cannibalize the linear-channel version of his brand that U.S. distributors have managed to sell into 43 million U.S. homes, saying data proves no such effect is taking place. To the contrary, the HBO CEO sees his streaming service helping sell other broadband-based products.

“I don’t think it’s a threat to their business,” he said. “Let’s talk about Comcast and Charter, Time Warner Cable. They have millions and millions of broadband-only customers. We are saying a very simple thing, why wouldn’t you want to take a product like HBO that helps preserve their broadband, and think about upselling to a skinny bundle? Why not take that product, make it part of the package and share the revenue with us? I must tell you we are having better conversations with some than with others but the proof is in the pudding.”

Plepler had nothing but kind words for existing partners including Apple TV, Android, Roku and Amazon’s Fire TV, but also made clear he is ecosystem agnostic, and is content to add the 10-15 million additional subs he projects are looking to add HBO, whether they come from the 70 million pay-TV subs who don’t currently get HBO, or elsewhere.

HBO Now launched in April for $15 per month. Plepler did not divulge just how many subs the streaming service has managed to sign up, but made it clear he was happy with the initial results. That said, publicly throwing down the gauntlet in front of non-participating distributors is an acknowledgement that having their distribution muscle could help grow the footprint for HBO Now even more than whatever the product has measured to date.