Oh, boy! As an American consumer, I'm even more perplexed what the hell they are.
Like 15 years ago, Rakuten seemed to be a normal ecommerce site. I think they bought buy.com or something to get a foothold in the US market. Then they pivoted to being some sort of cashback referral service.
I'm not really sure why that would lead customers to think "yeah, I want cloud storage from the people who made a weird janky digital simulation of the Piggly Wiggly Value Club Card!"
(AWS made it work because they could say "we have the infrastructure to host one of the busiest sites on earth, it's good enough for you", but Rakuten does not have that credibility in the US)
They do a lot of things, mostly related to online retailing in Japan. They bought Ebates, presumably to get all the shopping data they collect, it wasn't really a pivot. (Also they'd been doing financial-ish stuff like rewards programs before apparently. I went and read their Wikipedia article when I saw this post.)
It is common for SaaSS dis-services to charge a monthly fee for use. Usually one SaaSS site does not substitute for another, so if users become unhappy with one dis-service provider it is no easy matter to switch to another. When users become dependent on one, it can gouge them at will with repeated small price increases that over time add up to a lot. We view the loss of freedom inherent in SaaSS as worse than the cost in money, but when a dis-service has you over a barrel, the cost can be painful. Thus, even users who don't see deeper than the bottom line should beware of SaaSS.
This is an extremely misinformed take. I don't care if it came from GNU, it's still just bad advice. I'm someone who's worked in IT for years. It takes a lot of effort for a business to run its own on-premises servers. You need static IPs set up ($10 a month), buy server equipment ($1,000 minimum for something business-grade and reliable), have a system administrator on-hand to maintain it ($90,000 p.a. or hire a consultant at $150 an hour), and even more because you still need to do off-site backups. Then you need to deal with downtime if something goes wrong or you need to do a system upgrade. Then you have to worry about running out of capacity because the server's compute and storage resources are fixed. And now, because you're hosting on-site, the security of your premises and your cybersecurity are subject to PCI compliance audits if you deal with credit card info. Everyone deals with credit card info.
For most businesses, it makes no logical sense to do on-premises computing. Anyone can learn to use AWS in a matter of months and anyone can sign up for a business Google Drive account be done in ten minutes. If you set up your own servers, in the best case, it will take years to recoup your investment and you'll still have an ongoing headache, and when you do recoup your investment it might already be time to replace the hardware.
Nobody's saying to host it on-premises. The SaaSS article is advocating running software that you control on servers that you control. That's it. The server is likely in a datacenter, and its hardware could be owned by the datacenter, the customer, or someone else. It could be a virtualized host.
The SaaSS article is about software and services, not hardware.
People aren't storing massive amounts of data on cloud storage. For text document storage or even a moderate number of images, 10 GB is enough for many people.
Rakuten are the ones who make Kobo, a Kindle competitor that's more popular outside of the US - I have a Kobo.
Likely this is to eventually integrate into their Kobo device offerings, to let you upload your own .epubs (as opposed to Amazon .mobi). 10GB may be small fish for everything else but for ebook storage it's more than you'd ever need.
Rakuten is bigger than Amazon in japan. They are an online shopping service, mobile and broadband provider, bank, crypto exchange, traveling agency, credit card, fast pay service, online grocery store, and more.