[Jensson]

Depends on how big the quality difference is, if it is big enough then your product will grow exponentially via word of mouth, like Google did for example. That is just simple math, if you are good enough that people want to tell others about it then it will grow.

Problem is that today most technological needs are already filled by good programs so adding significant new value to peoples lives is extremely hard, so it is very unlikely that you can make naturally growing programs today on a tiny budget.

[necovek]

Google initially targetted a niche (geeks and nerds like us) with no-fuss, no-ads search experience where weight of the result depended mostly on how many citations it had. They were very present at conferences related to free software, for instance (which I'd consider investment in marketing).

And this group was the one in charge of "fixing their relatives' computers", so we were all too happy to tell them about Google: this is how word-of-mouth worked for them.