@giorgiamerlini I’ve seen some people have dual languages on one blog (like this one in English and Arabic -  http://www.wamda.com/wis3384), and others where they have the same content on two sites – the English on yourblog.com and the Italian on yourblog.it.  Also, you have the option for subdomains.  Maybe have the English on eng.yourblog.com and the Italian on it.yourblog.com.  

Having both languages definitely opens you up to getting more search traffic, social shares, and subscribers from both English and Italian readers which is a good thing.  

Alternatively, you can just add a translator to your website which was discussed in this thread a few months ago - http://www.socialmediaexaminer.com/clubs/blogging/forum/topic/blogging-in-two-languages-or-more/.  :)

@giorgiamerlini I suppose it depends on whether you want to get only Italian-speaking readers or not. If you sold a product or service in Italy, then it probably wouldn’t matter much if you were readable by American or English readers.
But if your blog is about Italy — say, a travel, food, or culture blog — then having posts in English will also help.

Then I would do both an English and an Italian version.

One way to make money from your blog is through affiliate sales. That’s where you sell makeup off websites where the companies will pay you a commission. Someone clicks a link on your website, buys some makeup, and you get a percentage of the sales.

If you did it only for Italy, you could fairly easily dominate that one market. It might be tougher to go after, say, all of Europe.