Reasons: 

• You can get a cool summer internship far away.
• If you get an internship: networking. (I still talk to my props master all the time). 
• You can meet other awesome technicians. They have a fun tech mixer at the beginning of the conference. (I still talk to a props master/carpenter/scenic designer type that I met at SETC last year.) 
• NETWORKING. (Meet people who can get you jobs!)
• Interview training. Even if you don’t get a job, you just got a ton of interview experience!
• Workshops. The classes are awesome. 
• There’s a little expo with cool free stuff/samples.
• Looking for transfer/go to grad school? There’s all sorts of booths for that. 

In summary: Go to SETC. You will not regret it.