Mobile Dev Memo trade blog. “The big question is: Are we seeing just short-term volatility where we can expect a move back to the mean, or is this a new normal?” Facebook advertisers, in particular, have noticed an impact in the last month. Media buyers who run Facebook ad campaigns on behalf of clients said Facebook is no longer able to reliably see how many sales its clients are making, so it's harder to figure out which Facebook ads are working. Losing this data also impacts Facebook's ability to show a business's products to potential new customers. It also makes it more difficult to “re-target” people with ads that show users items they have looked at online, but may not have purchased.