If you are concerned about data aggregation but still want to use FB, then at the very least don't combine your FB logon use with logons to other sites. Keep website logons separate. Make that the minimum you will do.
Brilliant advice everyone should follow!
One service, one account.
I know it's tempting to "make it easy" by logging in with credentials from other services, but all you're doing is sharing more of your personal information, habits, etc... to third parties. They are making money off you. When it comes to things like social media, you are the product, not the customer.