Digital assistants are arguably the hottest segment of consumer technology at the moment, but the pool of competitors is pretty shallow. Depending on how you measure market-share, the current lead is Amazon’s Alexa, found on devices such as the bestselling Echo “smart” speaker. Coming in second is Google Assistant, which is baked deeply into the Android OS as well as a growing collection of speakers and appliances. (For developers and other tech pros, digital assistants are a particularly vexing topic, especially with regard to monetization. How do you build revenue-generating apps for something that depends primarily on the user’s voice, and doesn’t necessarily need a screen? While Amazon has some ideas about that, the road forward isn’t clear—and it’s driving some creators absolutely nuts.) Amazon and Google aren’t the only companies in the space, of course, and rivals are pouring millions of dollars into their own digital assistants. Not all of those projects will succeed, however. Here are three that might end up reduced to the status of “also rans.”

Cortana

Microsoft’s Cortana hasn’t gotten nearly the same media love as Alexa and other digital assistants. Nor will the platform’s latest innovation—making Cortana skills accessible via Alexa (and vice versa)—likely move the needle that much. If Microsoft really wants Cortana to succeed, it will need to integrate the software into far more devices, including home appliances; right now, the only supported hardware is a… thermostat. If Cortana fails, it will serve as yet another example of Microsoft failing to capitalize on a popular trend. Remember that Microsoft came to the smartphone and tablet markets relatively late; former CEO Steve Ballmer initially laughed off the iPhone as an overpriced toy, and his attempts to catch up—by launching Windows Phone and acquiring Nokia—failed to impact the marketplace. Missing the digital-assistant boat would prove an equally disastrous move, given the increasing popularity of the format. All that being said, Cortana does have one thing going for it: Windows devices encompass a huge install base, meaning that the number of users exposed to Cortana is huge. But without a substantial mobile or IoT presence, Microsoft risks being left behind.

Bixby

Why did Samsung choose the name “Bixby” for its digital assistant? Probably because it sounds old-timey and fun, like the name of an English butler in a black-and-white comedy-of-errors film. Samsung’s enormous hardware reach—in addition to phones, it makes everything from televisions to refrigerators—means it could easily install Bixby throughout a user’s home. Sounds good, right? There’s just one little problem: Bixby has gotten terrible reviews. “The most frustrating part of the S9 [phone],” TechCrunch called it earlier this year. “I couldn’t wait to kick it to the curb,” Engadget offered last summer. And that’s just a small sample of the negative feedback. No bueno. Yet Samsung is forging ahead, this time with a device that will place it in direct competition with the Amazon Echo and Apple HomePod: the Galaxy Home Speaker, a high-end “smart” speaker loaded with—you guessed it—Bixby. The audio components are reportedly top-notch, but that won’t mean anything if the virtual butler inside is a complete moron. At this point, Bixby is looking like an also-ran. It would be a mistake to count out Samsung entirely, though: the company has a way of iterating past its mistakes, and there’s every likelihood that the assistant could become passable in a few generations. But that might be too late if Samsung wants to dominate the market.

Siri

No, Siri isn’t “doomed.” Apple has far too pervasive a reach, and it clearly has no intention of abandoning Siri anytime soon. That being said, the platform often seems eclipsed by Google Assistant and Alexa. In order to reverse that perception, Apple recently hired John Giannandrea, who also ran Google’s artificial intelligence efforts. With that kind of leadership in place, Apple clearly hopes that it can make Siri smarter and more powerful. Paired with a cheaper HomePod, that could mean a bigger and more successful push into living rooms. But those are all hypotheticals. At the moment, Apple is trying to catch up to Amazon and Google in terms of market-share. But at least it has more than enough cash to attract the talent it needs.