Often times when something like this is talked about you don't really hear about the reasons. Normally it's assumed that the business either went under or the owner(s) called it quits too early to really know whether or not they would have succeeded. This is where the researchers actually did a little digging and where how all this relates to internet marketing comes in.
Of the top reasons for failure, lack of planning, lack of focus, and being unprepared for the time requirements were all included. In online marketing these seem to be the top reasons.
First: lack of planning. The new marketer becomes excited about some idea. They jump in head first, purchasing domain and hosting with whatever random software they happened to find online. After doing some initial work they come to realize that they don't really know where to take this thing.
Second: lack of focus. Shiny object syndrome. Distractions. Or simply not having a tangible goal aside from "make money". The new marketer becomes discouraged or flustered and ends up not going anywhere.
Third: "So much for getting rich quick". The new marketer overestimates their own willingness to stick it out. Or perhaps they really did think that they would have overnight success. Then reality sets in and they come to the conclusion that this is going to take some time. Or maybe they already knew that but have no way of knowing whether it's worth it. Many will (and have) quit before they even reach this point.
I'm not trying to say that an online business is the same as a brick and mortar on main street. But there are similarities in the mindset. The mistakes listed don't necessarily have to lead to failure as long as they're caught and dealt with. Until more of those who would call themselves 'marketers' can come to grips with this it's the online startups that better match the 97% or whatever failure stereotype.
(I hope this was a half decent post. I don't normally do this.)