Do you use products from the same line?

I've seen that when looking at skincare products, it says it's good to use the same brand and same line.

I've never bought an entire skincare line from one brand, so I'm curious.

Does using products from the same line actually create a synergy effect?

Or is it just some kind of marketing?

Actually, just because a brand's toner is famous doesn't mean the serum or cream in the same line is famous as well.

I just use toners and serums from different brands.

I'm curious to know what the other Unpa members think!