Continental is offering 100 miles “for learning about the benefits of the Star Alliance network” and all you have to do is register.
If these miles post — and Continental is notorious for free 100 mile offers that never do — then it’s great, and could be helpful in averting mileage expiration for some. Personally, if I were using it to extend the validity of an account I’d take screen shots of the offer and of the page showing successful expiration, those should help dispute an account expiration if the miles don’t actually post.
(Hat tip to Dan R..)