Launched my product and now it's on day 7. I have a $60 budget on the ad test. I know a guy who said advertising your product on launch is stupid. For B2B, perhaps. But I am in the big B2C family.
But I think the most valuable thing you can get from an early ad campaign is whether your product is working or not; the common question, "Do people want it?"
My CTR is now on 3.55%, which indicates a good ratio of clicks to impressions. I know people kind of want my thing right now. It is also because I built my product upon pain.
But you pointed out a crucial thing: yes, it is still too early to conclude.
I think the average clicks-to-sign-ups rate is around 3%. There wasn't a lot of data or trends to observe.
I have also gotten valuable feedback from my friends. It taught me the same thing as you mentioned. You'll miss a lot of things during development. I've learned that before, I pivoted my product completely to something simple and different. However, there will still be things you miss; it is unpredictable. I concur.