Every new idea is just a mix of old ideas.
Here are my three rules for “stealing” ads ethically:
Rule #1: Never steal from your neighbor
Instead of copying my competitors, I draw inspiration from other industries.
For example, if I need a B2B idea, I’ll try to find it in a B2C ad library, like Lurzer’s Archive.

But it’s a nice ad nonetheless.
Rule #2: Limit yourself to 30 minutes
Ad inspiration quickly turns into procrastination.
So I browse ads for half an hour, then get to work.

Rule #3: Steal one element, not the whole piece
My client, AppsFlyer, wanted to target large companies that have outgrown their current tools.
So, while looking for inspiration, I found these two ads:

The fishbowl simply caught my eye.

And the big man in the small box reminded me of AppsFlyer’s target audience: enterprise teams locked into software built for startups.
Next, I googled “big fish in a small tank” and found this:

And here’s the final ad:

AppsFlyer’s audience knows.