Wow, how is it that there's only one instructional book to learn Serbian? There are many books to learn Norwegian out there (which I'm familiar with because I have learned a bit of Norwegian in the past), and fewer people speak it than Serbian.
Norway's economy is 7x that of Serbia (from Wolfram Alpha) and the Nordics do invest in this sort of thing.
Those are 2 very different places :)
I just think there's a lack of interest, which is a little sad. The culture is rich and fun, and the language is rhythmic and poetic. I wish more people would try to connect with their Slavic history!