Campari is one of the more popular apertifs. The ingredients are top secret, but it's believed to contain the infusion of sixty different ingredients, including rhubarb and ginseng. It's has a definite bitterness to it, but Joe Campanale sommelier/ owner of dell'anima, L'Artusi, and Anfora in New York's West Village, softens the flavor with his recipe for Roasted Orange Negroni Sbagliato

Follow Find. Eat. Drink. on Twitter: www.twitter.com/findeatdrink
Campari - Wikipedia, the free encyclopedia
Campari cocktails: 20 appetizing drink recipes.
Campari Cocktail Recipe - How to Make a Campari Cocktail
Top Campari Cocktails for Summer in Celebration of 150th Anniversary
I agree with the earlier poster about the potential enhanced bitterness from the roasted oranges, but the only way to find out is to try it and see.
This cocktail movement has really gone of the deep end.
When I want non-alcoholic Campari I roder San-Bitter which is very similar.
I was interested to see this story since I made a brace of Negronis before dinner this very evening.
Cheers.