I like most people on here have a landline and also a mobile. But other that the occasional 0845 number I never use it. Yes its good for incoming business calls but still think that £10 a month rental is way too high!!
I do things differently from you.
I have a BT landline and an Asda PAYG mobile.
Therefore, I make a fair few calls by landline. However, I route most of them via an override carrier which greatly decreases the costs.
The landline number is mainly about being contacted. I also have an 0845 number that maps to it. I give out all three numbers these days because, due to a great deal of misinformation about 0845 numbers, many people dislike phoning them.
The misinformation I refer to is when they are likened to 0870 or 09xx numbers. My 0845 number is charged at 3.5ppm to the customer. They only have to phone it for a few minutes on a first enquiry whereupon, if they become a customer, I give out my geographical landline number. I only did it this way at the start because I thought I would be moving and thought it would be better to just be able to point the virtual number to a new landline number rather than having to tell everyone about a number change.