Two cases in point: I needed to make a hair appointment for the wedding, so I called a woman who comes highly recommended. I told her so in the voicemail I left. I asked her to call me back ASAP, to let me know if she was available to style my hair.
She never called back.
3 days later, I tried again. No answer. Come to find out (not from her though!), she's busy that day and can't do my hair. So I just wasted 3 valuable wedding planning days NOT hearing back from her.
Second instance: a girlfriend sent me a text that one of her friends had 2 extra tickets to the Cubs game, and she asked if I'd wanted them. I said absolutely! So I called the friend of a friend and left a message, saying I was interested. This was Thursday.
On Saturday, I still assumed we were going, until I finally texted my friend, and she told me her friend gave the tickets to someone else.
Thanks for letting me know.
Seriously people, it's a common courtesy to call/e-mail/text/tweet someone back when they're trying to get in touch. Even if you don't have time to chat, just send them a quick text that you'll get back to them as soon as you can. We have so much technology now, there's really no excuse.