No, it's spam email. Though they do show ads for stuff you've already bought on their site, too. And notice that they can do all this while at the same time sending email asking you to rate your purchase of the thing you bought.
I've never gotten one of those either. I wonder if there is an opt-out that I opted out of 10+ years ago?
Edit: Guessing it is this:
Your Account -> Your Account -> Email Preferences and notifications: checkbox: Do not send me marketing e-mail
Yeah, it's an easy opt-out. I don't get them anymore.
Prime is the only streaming service I pay for because I think it has more to offer than Netflix. Generally, the free streaming content on Prime coincides better with what I would actually want to watch. Prime has a lot of new content and recently made some deals with studios to provide even more. If you're a parent, Prime basically owns the rights to stream most older Nickelodeon content (from the 1990s to this decade), and has other non-Netflix-streamed kids programs like Mr. Roger's Neighborhood, Yo Gabba Gabba (it's inane for adults, but man those toddlers love it), and Blue's Clues. If you've had Prime and canceled a year or more ago, the content has gotten a lot better (for adults, as well--it's not just kids programming they're adding). Prime has even stolen programs from Netflix (like Downton Abbey). I would check out what TV programs or movies are exclusive to Prime and see if it is or isn't your cup of tea. That is, of course, if you're looking for streaming services at all.
As for the free 2-day shipping and the controversy about bumping the prices to include the shipping cost -- I always comparison shop on the internet anyway. I think most mustachians would. Most of the time, the Prime price is the best price--at least for what I buy. I also have to account for sales tax here in Texas (Amazon has a distribution center here in Texas so we get charged sales tax on some, but not all, items). I've never overpaid because of laziness. And I primarily use Amazon for items that are very hard to find in local brick and mortar stores.
The only part of Prime I don't think adds much value is the Kindle Lending Library. It's content far too limited. Every month I'm faced with the same unappealing choices. While the video streaming service has worked to expand content, the e-book library barely has.
That's to say, I'll still keep Prime, even with the price hike. It's worth it to me.