We recently started running some facebook ads on our 5 pages, initially everything went off like a rocket whether its reach/clicks/likes which was great too see.
What has happend now though is one of the pages reach has just died its gone from 47,000 to 10,000. I have since optimised it for likes to see what that effect has.
I did read an article regarding paid reach and is said; Facebook defines reach as ‘the number of people who have seen your post in the first 28 days after a post’s publication [on both desktop and mobile]‘.
is this correct if so that would make sense, secondly if that is the case does it make sense to create new ads each month?
Maybe it's because they don't show the ad more than 2 or 3 times to an individual (my average is 1.5 times) and you've reached the limit of your target audience already? I am seeing the exact same effect - a new ad generates some good reach figures, then tapers off, sometimes pretty fast, much faster than 28 days. If you were to ride that "reach" wave, so to speak, I think a new ad each week (or, depending on your demographics, new ad for each weekend) is going to be needed.
@adsxx: thanks for the tip! One thing I noticed though is that after an ad has been paused, it tends to need a couple of days to start performing again. They seem to correlate ad views with CTR and a paused ad appears to have its CTR average either completely wiped off or somehow reduced, and the ad seems to need to generate the "right" CTR average (whatever FB thinks it should be) again before it gets a wide enough reach.