d> Note the number of marathons and the PR's that this guy has run - d> and his age. Look also at his reasoning.
My novice opinion is with others who say it may work for some but if you're not already experienced you better run some more miles.
One other point: someone who just loves daily running may use a marathon as justification for running 50, 70, 100+ mpw in 6, 10, 15+ sessions rather than (in addition to) the reverse, training supporting the race. The prospect of trying to run 42 km reasonably well helps keep me from giving some of those other life goals and obligations more time... or more likely gives me a somewhat rational excuse for doing so.
