There are two forms of spamming. One is spamming links
to get traffic;
the other is spamming links simply to get the attention of search
engines. Nofollow makes no impact on the former, but does mess up the
latter, and that's what we were aiming to deal with...
I wouldn't call those different forms, they are just different goals.
The spamming is the same in both cases - adding inappropriate links to
articles.