It's a matter of personal preferences. If I want to hear/talk to this person, as I haven't talked to them in a while and miss them, for example, I would surely call instead of message them. If I want to send information, but don't want to engage in personal conversation necessarily, then I would text. And of course, there is the case when you think a phone call would be inappropriate at the time - as the person might be in a meeting, or sleeping, etc.

Or it could have something to do with budgeting, even. Most cell phone plans in Bulgaria include free minutes to pre-specified numbers (they call it friends and family) so it would be cheaper to call them than text (very few plans give you free texts). So if you are cautious about your phone bill,you're likely to put that in the equation.

I hate voice mail. We've never had an answering machine. Heck, we got our homeline when I was four (there used to be long waiting to get a phone line). Very few people had answering machines actually. So when I got my cell phone, the first thing I did was to turn off the voice mail. It took me a while to start getting more comfortable leaving voice mails for clients but I still would very rarely do it when calling a friend. I guess we're just not good at monologues :)