That sounds like an insightful, but very quick, experiment! Running Facebook Ads for just one week is often enough to get initial feedback, though it's typically too short for Facebook's optimization algorithms to fully "learn."

Based on common experiences and case studies from running short-term Facebook Ad campaigns, here are the most frequent lessons people learn in that first week:

Key Lessons from a 1-Week Facebook Ad Experiment:
The Audience/Offer is Everything: In a short window, you quickly see that the success hinges most on who you targeted (the audience) and what you offered (the ad creative and the landing page). Poor targeting or a weak offer won't be saved by a short run.

You Need to Test Multiple Ads (A/B Testing): A single ad rarely works perfectly right away. A 7-day experiment often involves testing 2-4 different ad creatives/copy against each other to see which resonates best with the target audience (e.g., one image vs. one video, or two different headlines). One will inevitably perform better than the others.

The Budget Determines the Data: With a small budget for one week, the primary goal is often data collection (traffic, link clicks, engagement) rather than massive sales. You learn what your Cost Per Click (CPC) is and which audiences are cheapest to reach.

The Learning Phase is Real (and Short): You realize Facebook's delivery system takes time to learn and optimize. In just one week, your ad set might not fully exit the "learning phase," meaning the platform hasn't had enough data (typically 50 conversions in 7 days) to efficiently find the best people for your goal. Therefore, the results you get might not be the best your ads can achieve.

Ad Creative Dominates: Since users scroll quickly, the visual element and the first few words of the copy (the hook) are incredibly important. You learn which image/video stops the scroll and gets the initial attention.

The Landing Page Must Match the Ad ("Ad Scent"): You quickly find that if the landing page doesn't continue the exact message/offer from the ad, the conversion rate drops dramatically. This connection, known as "ad scent," is crucial.

Retargeting Potential is Built: Even if sales aren't huge, you've started building a "warm audience" (people who visited your page or watched your video). The next lesson would be to run a retargeting ad to this group, which is often far more profitable.

In short, a one-week run is a perfect initial test to determine your best-performing ad creative and identify a viable target audience before scaling the budget.