I get this a lot:
Thanks for getting back to me so quickly!
Thanks for replying so fast.
Thank you for your prompt reply.
I take special care about responding to people, regardless of the medium of communication. If you text me, I'll text back right away. Email? Minutes. Voicemail...well I'm getting better at that. But when I know someone has contacted me for any reason, I respond quickly. Why?
Because people appreciate it.
Many times in the work environment, people know I'm the wrong person to contact organizationally, but choose to email anyway. They know I will at least respond quickly and tell them who the right person is for them to contact.
Not only do I feel accomplished knowing people hear from me quickly, but I also see it as an advantage. Imagine if you were applying for a job. The prospective employer leaves a message on your phone and one other competing applicant. First to call back will most likely be hired, given a similar skill level. Or say the Pastor emails the entire staff asking about a link to the website. First person to respond looks most on the ball.
But there must also be balance. I used to have sound / banner / badge notifications for every application on my phone. Every email, text and message would command my immediate attention. This can be rude in some situations, and distracting at home while trying to spend time with family.
Now, I'm very picky about what gets sound and lock screen notifications on my devices. I don't want to be slave to email, but I still want to give prompt replies on a regular basis. The VIP feature on iPhone is a big help, but just being conscious and aware of who's trying to get a hold of you will speak volumes.
And remember, even if you don't have the answer to a question yet, still reply with something. Let people know you saw their message and they will feel instantly valued.