Alitalia offers a pretty screwy program, they ‘end’ the program and cancel all miles in the account every few years unless you earn back your existing miles. And this has nothing to do with expiration of an account for inactivity, they simply close their old program and start fresh.
That said, they’ve got a pretty impressive member-get-member offer going. They’re offering 25,000 miles for referring someone by September 30 who then flies two flights on Alitalia or Air One by December 31. Seriously. 25,000 miles.
The link for more details on the offer is in Italian, but iGoogle tells me that in addition, the referred member receives a bonus 1000 miles as well. And that’s on top of the 2000 mile bonus for first account activity within 3 months of joining.