Although the number of landlines in Slovak households is declining I still maintain mine. I pay some 400 Slovak crowns per month to Slovak Telecom, mainly for the sake of older members of my family who feel a lot more comfortable calling my landline than calling my mobile.
While there are financial considerations (i.e. calling mobile phone numbers from a land line phone in Slovakia remains pretty expensive) there are also some privacy considerations: calling someone's home telephone and reaching them means you will not be catching them in the supermarket checkout line, at a busy traffic intersection or in a cinema.
For me another advantage is that I know only very few people have my landline number and I can be pretty sure that it is the family calling (and the occasional telemarketer who I simply hang up on).
Many new businesses these days do not bother to install landlines - probably to save the money and hassle they provide a mobile phone number as their primary contact number. I would argue that this may be shortsighted for some, especially those who interact with an older clientele. There are lots of mainly older people who remain distinctly uncomfortable both calling a mobile phone in general (perhaps because they are used to the anonymity of landline calling from the time landlines did not have caller ID) and especially calling a mobile from their land line telephone.
If I were to operate a business that expects customer calls I would probably try to offer at least a mobile and landline contact number and perhaps even consider having a separate mobile contact with the several mobile operators. From a practical perspective having a contract with each operator allows to economise on outgoing calls. But also this maximises the chance that customers wishing to reach you by phone will be comfortable doing so.
What prompted this short writeup was my recent experience trying to make a hairdresser appointment. On the website the only phone number provided was a mobile, I phoned and said I would like to make an appointment. The lady on the other end surprised me a little: "Could you call back in about 10 minutes? I am away from the salon right now." Now that would ever happen with a landline...