Do you recommend 1 per ad? 1 Per Campaign ?
Thanks
Personally, it really depends.
I tend to do it on the campaign level, but only 2-4 ads per campaign.
Sometimes none, sometimes one, sometimes dozens.
Sometimes you want really broad audience as you get cheaper traffic generally, and the offer is very broad interest (I often start this way to get country/demo info), my FB rep recommends that I target this way but it's generally better for initial data than it is for profit.
If I'm making an ads targeted towards a specific group - Let's say for people who own Honda's in North America, I'd add:
You'd add Honda, Honda civic, Honda accord, Honda tuning magazine, Honda Canada.
You get the idea.
Anyway from lurking on here, I think a lot of people do things differently, so I don't think there's one 'right' answer to your question.
Yeah there is no right answer here.
I usually group them too.
Its Facebook just keep uploading ad's till the Facebook gods bless one with a high CTR and low CPC.
One main interest and a bunch of sub-interests that cross over heavily is going to yield the best results usually. I like to create a bunch of hyper targeted small campaigns and turn the losers off. Then I'll lump them together and turn volume up.