If you are unable to find out that 90 percent of people can't use a major feature that you thought would differentiate your product, you are missing all forms of feedback, including much more important sources besides analytics.
I disagree completely because I've seen it in practice.
A button turns out to be below the fold on common small screen sizes that a new designer forgot to consider. A bad translation results in 90% of users in a particular country misunderstanding something. A JavaScript library doesn't work on a common Android phone you don't test with. Latency issues make something virtually unusable from the other side of the country because of a single badly written function that's easy to rewrite -- but you still have to catch it!
You need ALL forms of feedback. It's not a question of some being more important than others. They're all important and play their own unique roles. Analytics is for catching AND debugging all the things that go wrong at scale in the real world, as opposed to the artificial and limited environments used for user testing.
One goalpost at a time please. 90% of users in "a given country" is not the same things as saying 90 percent of all users. Unless that country is so important that it's everyone, and again you needed to test that your product is usable in the first place.
And even so, while there are a lot of countries and languages, a collection of tests in all of them, which is all it takes for these examples, is not "big data". Again you are crediting analytics for things that people were fully capable of and responsible for doing in the days without traffic data. I realize it is great for the resume and sounds sexier to do "analytics" as opposed to just basic software testing (you should see what people are calling "AI" in other industries these days). And I'm certainly happy to agree that analytics has some value, say in improving wording and stuff that a single instance won't tell you, but again these aren't cases of that.
If you see in your backend metrics, that a button isn't clicked by a huge number of visitors you can start there and analyze. Common screen sizes are helpful, but more helpful is to look at the page since maybe other optimisations can be made, if that is the important button.
Similarly with languages, that you cans er from backend metrics.
More data seems always nice, but analyzing more data isn't making analysis simpler and there is a big privacy impact in analytics, especially when outsourcing to data collectors, who can gather data across sites. (Which then also gives Google information which services are interesting to user and can be integrated into search etc.)
> if you are unable to find out that 90 percent of people can't use a major feature
How would the users know they can't use a feature they don't know it exists?
Let's say you add a brilliant new feature X, but due to a bug the users can't load the code for that feature so they never see it. How would they know to submit a form feedback for a feature they don't know it's there?
Because when you're talking to them directly you ask them about it. This is what I mean by all forms of feedback.
I'm getting the impression that people are just ignoring all advice about communicating with customers in their startups and just throwing stuff out there to see what sticks. Besides being wasteful in doing stuff no one wants anyway, what if that bad feature crippled your product and your paying customers have permanently switched to a competitor the instant your change frustrated them? And now you're bankrupt and can't afford analytics. Relying on analytics as a crutch to catch these things was the mistake in the first place.
Fun story I actually had forgotten about till now: I briefly worked at a tiny startup out of my school in the ending days of the internet bubble, trying to sell a "data mining" software product. Way too soon before it was cool, sadly. It was really hard to make the case that people needed to pay us $100k for the benefits we could get from their data. And companies certainly weren't going to go for a pitch like "if you launch a broken product we will catch that fact". They spend a lot of money to be sure that doesn't happen already. We even had one major customer figure out that they could just have an engineer perform a simple counter over incoming communications that would catch all they needed to know, and hence they didn't need our product anymore. That was kind of the end for us, in fact.
