Every once in a while?

Question

Representatives from my recruiting company sometimes come to visit me, may be once in a six months in my office. Is it correct to write some words of appreciation to them as shown below?. "I appreciate your thoughtfulness to come and visit me every once in a while".

Answer 1

I would slightly reword it to: "I appreciate your thoughtfulness in coming to visit me every so often."

1. thoughtfulness + in + (V)ing
2. "every so often" and "once in a while" mean pretty much the same thing, but "once in a while" feels less frequent while "every so often" is more open to interpretation.
3.