I hate it when people say: I want to be a blogger but I don't know what to write about.
Then the go into a field like making money online and write a bunch of uninteresting posts.
There are however people like impaul99 who go to make a fairly
successful blog on making money online after I told them that it's a bad topic, so what do I know? I don't have a successful blog (or an unsuccessful one for that matter).
In general authority also doesn't have to come from personal experience. If I remember right impaul99 went out and interviewed a bunch of people on how they made there first 100 dollars online (or something similar it has been a while ago so my memory might be fuzzy).
He also went to make some money with affiliate marketing outside his blog.
The important thing is that you have data on which you make your recommandations.
A blog on which scientific research is interesting for money making online, probably also wouldn't necessarily need a person who already made money online.