Donating blood and plasma?

[zir_micalzo_prge]

In my first week in college there was this truck and that was looking for students to donate blood. They said they were giving out free movie tickets. 
Well I donated and definitely got the the ticket. Now months passed and I am being called everyday and sent emails about donating blood for plasma? 
I want to know what you all with experience think, Should I keep donating blood? Could the enemy has something to do with this? 

 

[centralforce6661]

Donating blood is fine from time to time if you are young and of a robust constitution.

If you tend towards weakness frailty, exhaustion and even ongoing general tiredness and digestive insufficiency then donating blood could worsen your health.