I must say that once again google has got us all scared of linking for promotion - which is one of the goals of course.
Interesting that you mention this, because a couple of months ago I had a brunch with some people from a CPM ad network I use. I was talking about how one gets afraid to promote one's site because Google might see it as "linkbait" or "overoptimization." I've avoided not only promotional linking but "guest posts" and all sorts of other forms of promotion that existed (or had equivalents that existed) long before Google. I joked, "It's as if Google doesn't want anyone but themselves making money online."
To my surprise, they nodded somberly and said that was exactly it. Now, they're a CPM company competing directly with Adsense, and that's their perspective.
That really solidified my choice to start doing whatever makes business sense, and whatever Google makes of it I'll just have to live with. Because at the end of the day, if some form of promotion is bringing you more traffic from sources other than Google, then if Google dumps you at least you still have that traffic.