How effective are paid Facebook ads?

depends a lot on what stage you're at. if you already know your offer converts, facebook can scale it fast. if you're still figuring out messaging, you'll burn through budget with nothing to show.

biggest mistake i see is people optimizing the ad when the real problem is they don't know why their good days were good and bad days were bad. that's what i'm trying to solve with Clarik -- https://getclarik.vercel.app -- still early but the idea is simple: tell you in plain english what's actually happening with your campaigns instead of leaving you guessing.

FB Ads definitely work but you have to provide value upfront rather than hard sell.

$5 is not enough you need to spend min $5/day for 5-7 days and test multiple copy, image/video and targeting and see what works best.

What did you use to promote the webinar? Hard selling someone a webinar when they’ve been never heard of you will be difficult. Try promoting 2-3 posts/videos that educate your audience first, then ask for the webinar signup.

Without a warm audience not very effective. Targeting is now harder than it use to be. With a custom audience your chances increase. Video is better than space ads. Let me suggest more text and less picture, if you choose space ads. Don't expect the viewer to click to your landing page through a CTA, most will not (they look around on your facebook page, then leave). Most of the viewers are on mobile. Expect to pay $0.90 a CTR. I ran tests and spent $22 a day, while I converted 2 a day from video. These tests took me three weeks to fine tune. Don't run ads on days that have sports on TV.

How effective is a hammer?

You need to know how to use the tool to maximize ROI.

FB ads are: Sales Copy + Offer + Relevant Traffic = Customers

Make and test multiple $5 ads to experiment, test and learn what works.

Facebook ads are effective infact any social media ad is effective when you target your audience well. Usually, it is advisable that when you start at first, you run the ads on daily bases instead of just the monthly stuff. That way it's easier to monitor and target the audience well.
Subsequently when you have understood what your audience are after you can then do the monthly stuff

I previously posted my FB Ads experiments https://www.indiehackers.com/forum/9335aed90d

Since then I have tried a few more and got varying results from $9 a click to $0.17 per click. Because you might not know what content/copy will work, you can make posts on your page and share them, then see which has the best response. Then you can boost that post, or make a similar one.

During Black Friday I bought Connect Explore from connectio.io . It's suppose to let you fine tune your targeting. See their intro/explainer video. I will experiment with this once I have decided what to Boost.

There are so many factors when we speak about Facebook Ads. But usually, if you campaign is well targeted, you will need to run it at least 3 days at 5$/day minimum in order to calibrate and see results.