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All signs indicate 2016 is a big year for Google Fiber, as the broadband Internet and cable business under Alphabet plans to break ground in a slew of new markets.

In its existing markets, however, there are some signs that one part of Fiber’s business — the pay TV side — is struggling to get off the ground.

New data cobbled together by MoffettNathanson shows tepid growth among Fiber’s video subscribers in its initial metro areas during 2015. Fiber had 53,390 pay TV subscribers at the year’s end. That’s up from just under 30,000 in 2014. In Kansas City, Kan., Fiber covers 22.6 percent of the cable market, up from around 13 percent last year.

But the growth has slowed considerably: It grew at 136 percent for the last six months of 2014, and just 78.8 percent for that period in 2015. In Provo, Utah, where Google bought the municipal network three years ago, Fiber added just 65 video subscribers in six months.

That said, the numbers point out that Fiber’s priority lay in its broadband service, where it does not have to compete with entrenched cable bundles. As Re/code’s Peter Kafka noted with these estimates a year ago, the pay TV business is just a supplement to its super-fast Internet.

And yet it’s a rather blistering report from MoffettNathanson. The firm notes that the figures would make Fiber’s video business one-seventh the size of the smallest cable business the analyst firm tracks. “One can’t help but feel that all of this has the flavor of a junior science fair,” the report reads.

The figures do not include Fiber’s broadband numbers, which it does not have to report to the government (and opts not to share). Growth in that is almost certainly higher.

Still, laying fiber optic cable is an expensive endeavor. Particularly when the big telco rivals like AT&T are attempting to mount blockades to Fiber’s expansion.

Ruth Porat, CFO for Google and Alphabet, has repeatedly stressed to Wall Street that Fiber will be a chief recipient of the company’s ample capital spending. Earlier this week, at a Morgan Stanley conference, she said the company is “really pleased with the progress” on Fiber.

The MoffettNathanson report, though, reveals that the Street is starting to get antsy with the unit’s feeble growth.

“As ever,” the report concludes, “Google’s presence in the press and inside the Beltway (and in investors’ minds) is wildly out of all proportion to its actual size.”