Threads on X used to be the hot format. Then everyone started doing them and now most threads underperform a single tweet on the same topic. The format isn't dead, but it's been overused. The fix is to thread on purpose.
Here's the rule. Thread when, and only when, your idea actually needs more than 280 characters. Otherwise post a single tweet.
When threads work
Threads work for two things.
The first is a sequence with a payoff. A story where each tweet builds toward an ending. A walkthrough where each step depends on the last. The reader keeps tapping because they want to see how it lands.
The second is a list of distinct units. Five mistakes founders make. Seven tools you actually use. The reader scans, lands on one or two that match their thing, and bookmarks the thread to come back to.
If your idea isn't a sequence with a payoff or a scannable list, it's a tweet.
When threads fail
Threads fail when they're a single argument that's been padded out. You see this all the time. A point that fits in two sentences gets stretched into eight tweets, each one a slightly weaker version of the first. People tap once, see the second tweet is just the first restated, and bounce.
A short, sharp tweet would have done better. The thread is just a long-form way of being less interesting.
How to know
Write your idea as one tweet first. Don't think about format yet. Just write it.
If the tweet feels finished, ship it as a tweet. If you read it and feel like you're cheating the reader because there's a story you cut out, write the story as a thread. The reader's curiosity is the test, not your word count.
The first tweet of a thread
If you do thread, the first tweet is everything. It has to make the reader want the second one. The way to write it is to say the punchline, not the setup.
"Here's why most pricing pages fail." That's a setup. Skip it.
"The cheapest pricing isn't the lowest one. It's the one with three tiers." That's a punchline. Now they want to know why.
Punchlines first, proof in the thread.