Mass Texting

I got chewed out by my friends for mass texting them. I asked four people if they wanted to hang, but I used the same message, just sent it to four different people. They took it as an insult, as if I didn't actually want to hang with them. I wouldn't have sent it to them if I didn't want to hang. It's not like I sent it to my entire contact list. From now on I will either begin every message with their name, so they know it's personal, or a disclaimer stating, "THIS IS A MASS TEXT".