Contact management, 2017
Many sites have different bonuses eg yahoo can import fb while fullcontact connects with twitter. I don't think its good to leave contacts on only one site , just incase one is down.  I also like having 'hard copy'. I do this every so often.


Mac Sierra
  EXPORT contacts->  all contacts -> edit -> select all (see count change) -> edit export-> vcard
 
  IMPORT to fullcontact (FC) site  ,
    settings -> import , selecting  the Mac-vcard from above
     link your social media contacts like twitter,  and  linkedin  if you wish
    EXPORT     fullcontact site:   backups-> select latest file
 
    IMPORT into yahoo, select contacts icon, select  import contact , add gmail and facebook if you wish
    EXPORT actions dropdown  select yahoo-csv , or mac vcf
   
    outlook IMPORT, select a file from above  and allow to select  a file  , then click upload , located  top left of popup box .  However  there is 2k number of contacts  limit and 5mb file size upload limit.
     EXPORT , outlook/hotmail : manage ->export
   
 IMPORT gmail , more-> import
 export gmail, select all the checkbox, more ->export , making sure to select ALL (third radio button)

 now import the gmail into Mac Sierra, file-> import

This process allowed me to save facebook, linkedin, google+ and twitter contacts and finally all in one file on my mac, where i can permanently store on backup drive