Netflix's next explanation for bad US subscriber growth: the Olympics

Over the last year, Netflix has put forth a few interesting explanations for flagging subscriber growth in the US, and it's already laid the groundwork for another one.

The first came last October, when Netflix explained disappointing US subscriber growth on the transition to chip-based credit and debit cards. According to Netflix, those new credit cards often have a new number or expiration date, requiring subscribers to update their payment information online in order for their subscription to continue.

In a letter to shareholders, Netflix said its forecast for Q3 2015 was off due to higher-than-expected "involuntary churn," or involuntary cancellations, because of the transition.

The second explanation came in July, when Netflix blamed its US subscriber growth shortfall on media chatter about its price hike.

"Churn ticked up slightly and unexpectedly, coincident with the press coverage in early April of our plan to un­grandfather longer tenured members and remained elevated through the quarter," the company wrote.

People read about Netflix raising prices on some members, and they cancelled. This held down net subscriber growth, the company said. Netflix added 160,000 subscribers versus Wall Street estimates of 509,000 (and Netflix guidance of 500,000).

And if Netflix misses forecasts for this quarter, it already has another explanation prepped: the Olympics.

"So with an assumption of a hit from the Olympics which largely affects us in the past on gross adds, or on new subscribers coming in, that's going to affect in terms of a year-over-year trend," David Wells, Netflix's CFO, said on its last earnings call. "We expect that to be a meaningful, a small but still meaningful, impact on the quarter. Negative impact."

If Netflix puts out disappointing subscriber growth numbers again next quarter, the groundwork has already been laid for a potential reason. What you can bet Netflix won't say is that it is approaching saturation in the US.

But some observers think they should.

"They're trying to give reasons why their subscription rates are down, and they're not reaching the same rates," Michael Goodman, director of digital media strategy at Strategy Analytics, told CNBC. "The answer to me is simple: Especially in the US, they're reaching saturation. It's a flat-out numbers game, and they're on the backside."