Twitter’s unconventional path is well-documented at this point. From failed podcasting company to playground sketch (actually, probably not ) to a revolving door of CEOs fueled by founder and board infighting has emerged what is, even after yesterday’s stock plunge, a $23 billion company. And, more importantly, a product absolutely beloved by many of its users, including me. You could argue it’s the canonical example of how nothing matters but the product.

Maybe.

One of the most common Silicon Valley phrases is “Product-Market Fit.” Back when he blogged on a blog, instead of through numbered tweets, Marc Andreessen wrote :

The only thing that matters is getting to product/market fit…I believe that the life of any startup can be divided into two parts: before product/market fit (call this “BPMF”) and after product/market fit (“APMF”).

When you are BPMF, focus obsessively on getting to product/market fit.

Do whatever is required to get to product/market fit. Including changing out people, rewriting your product, moving into a different market, telling customers no when you don’t want to, telling customers yes when you don’t want to, raising that fourth round of highly dilutive venture capital — whatever is required.

When you get right down to it, you can ignore almost everything else.

I think this actually gets to the problem with Twitter: the initial concept was so good , and so perfectly fit such a large market, that they never needed to go through the process of achieving product market fit. It just happened, and they’ve been riding that match for going on eight years.

The problem, though, was that by skipping over the wrenching process of finding a market, Twitter still has no idea what their market actually is, and how they might expand it. Twitter is the company-equivalent of a lottery winner who never actually learns how to make money, and now they are starting to pay the price.

The price I’m referring to is the truly disconcerting slowness in user growth and engagement that Twitter reported earlier this week. Twitter reported they increased monthly-active-users (MAUs) by 5.8% from the previous quarter, and 25% year-over-year (YoY), and that timeline views increased 15%. That was down from a 30% YoY increase in MAUs and 26% increase in timeline view last quarter. On the flipside, Twitter posted excellent financial numbers, increasing revenue by 119% YoY, and increasing their ad revenue per MAU by 65%. This too, though, is very unconventional. Ad-supported services are supposed to grow their user base first , and then figure out how to monetize later.

This actually is about what I predicted back when Twitter announced their IPO. From There Are Two Twitters; Only One is Worth Investing In :

If an advertiser wants to reach someone like me – and they certainly do, given my spending habits – Twitter is by far the best way to find me. Were Twitter able to consistently capture this signal and deliver effective ad units that caught their user’s attention, they could command some of the highest average revenues per user on the Internet.

The problem for Twitter is that getting a user as finely tuned as myself is not at all an easy process. My interests are so easily identified because I constantly edit who I follow to make sure my signal-to-noise ratio is as high as possible. However, this sort of behavior is totally unnatural and overwhelming to a new user. I hesitate to tell others how valuable I find Twitter, simply because I don’t know how to explain to them how to make Twitter as useful to them as it is to me.

Nothing has really changed: Twitter continues to know a lot about me and other heavy users, and is figuring out how to monetize that, but there just aren’t enough people like me. I know Twitter is trying to spin MoPub as giving them access to a billion users, but without the data derived from Twitter usage, those billion users and the ad impressions they see are just more undifferentiated inventory; there’s a good reason display ad companies are worth a lot less than social network ones.

What Twitter has is a marketing problem. To be clear, while advertising is a part of marketing, marketing is about much more than advertising. It’s also about understanding your market, what their needs are, and how your product meets those needs. I continue to see little evidence Twitter has any idea, and I think their accidental success is largely to blame.

An interesting side effect of Twitter’s inability to articulate their core value prop is that anyone and everyone has advice for how they might improve (including me!). Combine that with the fact that Twitter serves so many different use cases – real-time news, de facto RSS reader, public chat, just to name a few – and you have a paralysis of choice not only for new users but also for Twitter’s marketing and onboarding teams.

So why not embrace the complexity? Instead of trying to teach new users how to built a curated follower list, build the lists for them. Don’t call them lists, though; embrace Twitter’s TV connection and make them “channels.” Big basketball game? Go to the basketball channel, populated not with the biggest celebrities but with the best and most entertaining tweeters. Build similar channels for specific teams in all sports. Do the same for Apple, Google, and technology; liberals, conservatives, and politics in general; have channels for the Oscars, the Olympics and so on and so forth. And make them good , devoid of the crap that pollutes most hashtags and search results. If the ideal Twitter experience is achieved with a curated list, then provide curated lists and an easy way to switch among them.

Now you have a value prop: easily join the conversation about what is happening in the areas you care about, without the months-long process of building a perfectly customized Twitter feed. Oh, and by the way Ad Person, here is a very easy-to-understand ad unit built around a specific topic filled with self-selected followers.

Sure, this is a bit of a dramatic change, but there’s no need for individualized timelines to go away. More importantly, Twitter needs to do something dramatic. $250 million in revenue is nice, but:

LINE is mostly strong in countries that Twitter isn’t, but the important point is that more and more channels are competing for advertiser’s dollars. Twitter is in real danger of being reduced to a niche; useful for reaching a specific type of audience, but an afterthought for meaningful ad spending, and that certainly is not worth $23 billion.

Twitter is truly a special company with a special product, but not even they can escape the fact that product is a necessary but insufficient ingredient. Market matters, and it’s past time Twitter found theirs.