Nikosandros
Golden Procrastinator
It looks very much like that Castle Ravenloft (and I assume also Wrath of Ashardalon) are doing very well indeed for WotC.
Three in one year doesn't fit my definition of saturation.
I suspect you're not an avid board gammer. People like expansions and variations on board games as much as they like expansions and variations on RPGs.Three versions of the same board game? And its practically 4 in a year.
Most people probably just need one. But maybe they want two.