Typically Unknown appears as the name for 3 reasons:

1. You are using cc@app.pipelinecrm.com to track emails in our system and sending emails to people that do not exist in our system yet. Upon sending the email to the new person, we generate that person profile with only the email address if their email address is not associated with a name in your email contact list. 
2. When importing you did not map the first name field and the field ended up blank. 
3. You imported data into our system and your spreadsheet was missing data for those people.
4. The person was manually added without a first or last name.