[ZoFreX]

There are two modes of marketing mail I've seen increase massively over the last year or two (note: completely subjective 'study' based on my own inbox):

1) "Screw your choices" spam - despite figuring out the Mensa-challenge-esque puzzle of which checkboxes to check or uncheck, when signing up for a new account the company opts you in to marketing emails anyway.

2) "Blast from the past" - a I used to use years ago has decided to add every single email address they've ever seen to their mailing list, and I'm suddenly seeing emails from them. To me this looks a lot like the desperate throes of a dying company - I believe Yahoo pulled this at some point this year. Amusing variation: My sole contact with one company was a complaint email, which they did not reply to. Two years later they started sending me marketing emails. No, thank you.

When it comes to unsubscribing there's another trick I've seen on the rise, other than the ones you already listed: An unsubscribe process that takes weeks. The page says something like "You will be unsubscribed within 28 days" and you keep getting spam in the meantime. I believe at least some of Yahoo's services do this, too? There are two main variations for this one: companies that do actually remove you after 28 days, and companies that don't (I assume it's just a distraction tactic and they hope you'll forget).