When internet marketing was first catching on there were fewer people to target. Consequently the internet marketer could simply market to anyone on the internet without having to worry about things like industry niche and so on. There was simply no need for targeted marketing. Back in those days the range of products too had a near universal appeal that again mean generic marketing for the whole net. The only concern was to reach as many people as possible regardless of any demographic variation.
Things have changed drastically with the internet