She has had 6 (soon to be 7) consecutive Platinum albums since 2006. All six of them sold at least 3 million copies WW even though they were released back to back. Now, releasing an album every year without making people sick of her is a big accomplishment in my opinion. Not everyone can pull that off and make millions of people buy an album from the same artist every year. I guess the biggest reason that people call her a poor album seller is because she never had a 15-20M selling album like some artists. This reminds me a lot of Madonna. She never had a 30-40M selling album either but she had consistent good album sales unlike artists like Alanis Morissette who had one massive album and then started to downfall in sales.(Of course Madonna's album sales were a lot better than current artists tho) Rihanna is like that too, she gets good consistent sales instead of getting one big massive era and then slowly fading with the following albums. Another excuse that some people use to discredit Rihanna's album sales is her amazing single sales. But artists like Pitbull, Flo Rida, Kesha and Ariana Grande have amazing single sales too but they still can't come close to Rihanna's album sales (but Ariana still has a chance to get bigger).
So what do you think?

Is her album sales are underrated?