If you want to share data with an individual that does not have a gmail account (either through Seacrest or not), please follow these steps:
Open Drive and select the file you wish to share. Right click it, then click Share.
Click Advanced. Where it says "Who has Access" it defaults to Private and the File Owner. Change this by clicking then selecting "On - Anyone with link". Click Save.
Now enter the email addresses of those with whom you'd like to share the file. Allow the appropriate Access by clicking the Pencil icon, and select either Edit, Comment or View. Click Done.