For this week only, you can get a year of Marvel Comics' digital back issues service for less than $5 a month.
Marvel Unlimited features a huge library of old and (relatively) new digital comics — more than 17,000, according to the service's website. Basically, it's Netflix for Marvel comics. It features only comics older than six months, but instead of paying individually for issues, as you would on Comixology, you pay a subscription fee for access to the service for a month or a year. Perfect for catching up on, say, Thor.
Normally a year of Marvel Unlimited will set you back $69, but with the code TREAT at checkout, Marvel will knock the price down to $55.20, or $4.60 per month. Just make sure you get it soon: the deal ends at the end of Cyber Monday, Nov. 30.