The benefit of having multiple campaigns is that you can take more than one of the 7 RHS (Right-Hand Side) ads.
In Google, you can serve your ad in only one of the 10 spots. One ad per domain. But apparently Facebook doesn’t enforce this rule.
In outdoor advertising (such as on subway trains), a company will buy all the spots. It’s called a “take over”. Research shows that having one ad on each of twenty trains is less effective than having all 20 ads from one train.
Readers, do you think double-serving is a great idea or spammy?