Good Morning!
Question time again

I had a PC contact me via Twitter, he had looked at my website and thought it looked like something that may be of interest to him.
I responded thanking him for checking out my site, and to feel free to contact me with any questions.
My question is: How long do you wait before following up with them? What are some good ways to bring it back up? (without sounding desperate/hounding/etc

I don't want to fall off the radar with them, but also don't want to seem pushy.
I appreciate any ideas!!
Thanks!