This is also very important information to make known. There is most definitely risk involved. If you can't float the money for up to a few weeks then be careful with how much you buy. This is one reason I recommend BFMR as a starting place. They pay out very quickly via ACH and their check in times are fast. When you build confidence in the basic premise then you can expand from there. I've certainly dealt with a few of those issues and lost money here and there, but volume makes up for any losses.

Yes Rakuten is one of the portals, but there are many more. Like mentioned look at cashbackmonitor for options. If I could recommend another website that's not entirely MS related, but one that I find to be a helpful, data filled, no frills website it would be Doctorofcredit.

That's also a good point about 5% cards. There are a number of 5% cashback cards that would be a better use than a 2% MR earning card. While I make use of the Walmart, Amazon, and Freedom Flex 5% cards I don't yet have any of the others. I only started on this journey last year and unfortunately did not start at say 1/24 for cards. I'm always learning something new and there's always more to learn.