Basing myself on the activity of the forums, I find that very unlikely.
HoI2 and DD +62.000 threads, +820.000 posts
EU2 +42.000 threads, +887.000 posts
EUIII +31.000 threads, +463.000 posts
HoI 1 +30.000 threads, +355.000 posts
Victoria +25.000 threads, +339.000 posts
CK +14.000 threads, +197.000 posts
EU1 +10.000 threads, +124.000 posts
Rome +4.000 threads, +54.000 posts
HoI3 +2.000 threads, +56.000 posts
Diplomacy +1.000 threads, +12.000 posts
Of course these numbers don't say anything about the exact sales-figures but they are a good indication