I have a landline at the moment but dont advertise it and only have one elderly customer who prefers to use it (although recently she has bought a mobile and rang me last week on my mobile number - bless she's 92 !) and only gave it to her as she asked.
I dont want to be disturbed on my landline with work of an evening or trawl through loads of answerphone messages plus its not strictly a business number, I have a work mobile and a personal mobile.
I recently had one new customer choose me from the directory because I had a mobile number (I know I could have had both) and they wanted to contact me straight away, they said they picked me out of the list for that reason and no other.
So in my opinion it really does'nt matter.
I suppose to some people it seems more trustworthy to have a landline but I've never really understood why, the number could still be ex directory.
If I were to need a tradesman I would always ring their mobile, more likely to get through to them straight away or replied to quicker, we dont work from home afterall