entries don’t grow up

I tryied the plugin in the free version but i’m not sure it’s working for me:
when i subscribe the giveaway with my email i get my first entrie (Your Current Entries: 1) but if i try to share in twitter by clicking the twitter button, then i still see “Your Current Entries: 1” and this happens also if i give the sharing url to a friend of mine wich, from a different device / ip, visit it. So entries are not increasing.