Both can, yes.

Some can't sell an album with several

Yes and without any gimmicks

YES.

Yes Beyonce can

I did not ask about gimmicks. But you instigated my curiosity. Who is using them though?

Adele can. With only ONE smash hit, she sold over 18 million worldwide.

gimmicks don't sell millions of copies of an album and for some hit single sadly don't either .
gimmicks don't affect the critics
gimmicks don't let you still be #1 on iTunes 5 weeks later (currently #2)

Well yes. We know Adele is simply on another level. Not everyone's albums scan above 10M copies WW even with hits.

We'll never know.

gimmick
ˈɡɪmɪk/
noun
a trick or device intended to attract attention, publicity, or trade.

Ehm you clearly don't know what the effect of a gimmick is...

that perfect storm

yes

Why Rih didn't sell the same amount, with a #1 9x smash hit?

That's how it almost always works?

Popgirls either sell albums or sell singles, the real accomplishment is when they sell both like very few albums have managed since 2013 (1989, Prism, etc) or when they sell a huge amount of albums like 25.