WiFi Service

Yesterday i went to a restaurant. 
I saw there was a WiFi Service, so I asked for the password. The waitress told me 'eat first', so i placed my order. 
After eating i asked again for the password, and again, she told me eat first. Feeling frustrated, i ordered black coffee. After coffee, again i asked for the password. They told me eat first. Then angrily, i walked to the restaurant manager and asked for the password. He replied eat first!!. I was about to explode, when i finally saw a sighn on the wall... WiFi password= Eat first