Something to look forward to: Disney's upcoming streaming service, Disney+, not only looks like it'll be a compelling product, especially for fans of Star Wars and Marvel, but it's also cheaper than rival Netflix. And if you sign up for three years, it'll work out even cheaper: $3.92 per month.

Disney+ is set to arrive on November 12 and cost $6.99 per month or $69.99 per year, undercutting Netflix's $9 to $16 per month plans. It sounds like a good deal, but there's a way to get the upcoming service even cheaper, providing you move fast and don't mind making a long-term commitment.

If you're a member of Disney's official D23 fan club, which includes a free tier, you can take advantage of a limited-time promotional discount and sign up to a three-year Disney+ subscription for $141. That works out at $47 per year---33 percent off the normal yearly price---or just $3.92 per month.

The offer is available to "general," "gold," or "gold family" D23 members, but only until Monday, September 2. Even if you're not currently a member, you can sign up for the free tier now and claim the offer. So many people tried to sign up that it crashed the membership page, but it's working again.

Signing up for three years on an unreleased product might sound risky, but it does mean a 40 percent saving over that time. With Disney+ featuring new Star Wars content including a series following a young Obi-Wan Kenobi, with Ewan McGregor reprising his role as the Jedi master, expect plenty of people to snap up the offer.