After one of the industry’s most buzzed-about upstarts announced this week that it is shutting down, questions have mounted about the viability of e-book subscription services. Oyster—billed as the Netflix of books—confirmed last week that it will cease operations sometime in 2016.

It was revealed that some of the Oyster team will move to Google, fueling speculation that Google has acquired Oyster and might be angling for a subscription service of its own—a possibility that has tantalized industry observers. But sources said that Google has no immediate plans for an e-book subscription service, and that the company worked a deal to pick up some of Oyster’s talent, and to otherwise “soften the blow” from its failure.

Launched in 2013, Oyster offered subscribers access to more than one million e-books for a monthly fee of $9.99. The service drew praise from readers and gained traction with publishers (including three of the Big Five) by offering a model that paid publishers their full retail cut for e-books read by subscribers. But Oyster’s failure has amplified criticism that the subscription model is not sustainable, following on the heels of the July closure of Entitle, a similar service, and a recent announcement by Oyster’s main rival, Scribd, that it is scaling back offerings in certain genres.

Smashwords founder Mark Coker speculated, in a post on the company’s website, that Oyster and Scribd were facing the same headwinds: the cost of paying for their subscribers’ reading consumption is simply exceeding the revenue brought in from monthly subscription fees. In July, Scribd (which, like Oyster, pays publishers their full retail cut for books read by subscribers) was forced to cut romance and erotica offerings, because romance fans—notoriously voracious readers—were apparently reading far more than expected, driving up Scribd’s payments. Scribd executives have not commented on their plans since the Oyster announcement was made.

But industry observers warn that the failure of Oyster’s business should not be seen as a failure of e-book subscriptions with consumers. “There is a consumer appetite for mass market subscription services,” said Andrew Savikas, CEO of Safari Books Online, a long-running and profitable e-book subscription service that specializes in technology and business titles. Echoing Coker’s observations, Savikas said the cost of paying full retail price for content and the cost of acquiring new customers may not match what is generated in revenue.

Justo Hidalgo, CEO of 24 Symbols, a European e-book subscription service, also emphasized that there is growing demand among consumers for models based on “access over ownership.” But, he stressed, “you need high-quality content.” To attract better content, Hidalgo says he switched 24 Symbols to a payout system similar to Oyster’s—publishers are paid based on list price once a percentage of the book is read. But even though that model has attracted many more publishers—24 Symbols grew from offering titles from several hundred publishers to more than 3,000—Hidalgo says there is now much less revenue for him to sustain the business.

“We needed to grow, but paying on the wholesale model might not work,” Hidalgo said. “Publishers need to understand that. If publishers want e-book subscription to be a viable channel, we need to have win-win terms, rather than win-lose terms.”

Both Savikas and Hidalgo offered a variety of possible, albeit admittedly imperfect, tweaks, including caps on consumption, tiered levels of access, and revenue-sharing formulas. Hidalgo suggested that future e-book subscription models might emulate cable TV, with lower-priced basic e-book packages and premium add-ons for specialized access, whether for frontlist titles, or genres such as romance and science fiction.

Meanwhile, supporters of e-book subscription access say that publishers should not only want the model to succeed, but that they need it to. Consumer habits are changing in a mobile age dominated by smartphones and tablets. Quick and easy access to content is now expected. And as streaming services such as Amazon, Netflix, and Spotify fundamentally reshape consumer expectations, it is difficult to believe this shift will not impact the book business.

At a well-attended BEA panel this summer, Scribd v-p of content acquisition Andrew Weinstein stressed that subscription access should be viewed as a promising new channel for e-books at a time when retail has flattened and become more concentrated. “It’s about a balance in the ecosystem, and I would argue that the ecosystem is way out of balance right now,” he said, alluding to the elephant in the room: Amazon.

Amazon, of course, has its own subscription service, Kindle Unlimited. Under its model, Amazon pays publishers in Kindle Unlimited from a monthly revenue pool (the amount of which Amazon unilaterally sets) according to pages read, terms deeply unsatisfactory to most traditional publishers and authors. Currently, Kindle Unlimited participants (mostly self-published authors) earn roughly a half-cent per page—about $1.50 for a 300 page-book. Indeed, the head of one large publisher said he would support a standalone subscription service on principle, as an alternative to Amazon, as long as the terms at least “reflected the value of our content.”

Notably, all three of the Big Five publishers that work with Oyster and Scribd have reported excellent results. At last year’s Frankfurt Book Fair, HarperCollins’s CEO Brian Murray said e-book subscription services were the most promising of all its new ventures. “Subscription has turned out to be very successful in really merchandising and mining the backlist,” he said. Macmillan expanded its subscription offerings through Scribd and Oyster over the summer. And in a twist of timing, the announcement of Oyster’s demise came just days after S&S CEO Carolyn Reidy praised e-book subscription services during her keynote address at the BISG annual meeting in New York, telling attendees that Scribd and Oyster haven’t cannibalized S&S’s print sales, and were driving both revenue and discovery.

The question now is whether publishers, authors, and agents have seen enough good from subscription (and enough bad in the current retail market) to support a more sustainable business model. Is the value of the marketing, discovery, potential data, and the addition of a new revenue channel itself (especially a channel not dominated Amazon) enough to entertain a change in terms? Perhaps, but getting there may not be easy. “While some authors would do okay taking less per book in a subscription model, whether because they are building a brand or making old books newly discoverable, most will lose money, and a lot of it,” said Authors Guild executive director Mary Rasenberger, stressing that content included in subscription packages would need to be evaluated on a book-by-book basis. “Asking everyone to take a cut to support a business model that works only for some is a nonstarter.”

At BEA, Scribd’s Weinstein acknowledged that some publishers feared that the model of paying full retail prices for books read in subscription plans was too good to last forever. “But everything is too good to last forever,” he added. “Ask publishers if they are being paid the same amount from their retailers they were five years ago.”