Is it pointless to use a down mattreess topper on a memory foam mattress? Can I use both of them together? Will it make my bed...

Can I use both of them together? Will it make my bed more comfortable? Or is this lately a waste of have both?
What is the best road to swing posters...
Answers:    No it is not pointless at all. I currently sleep on a pillowtop mattress next to a two inch memory foam topper covered by a down mattress top. It is decadent and I highly recommend it, the one and only issue I have have is you need really thoughtful fitted sheets for it to work.
What can I do to bring topical life...
I have a pillow top and use a barb /down topper on my bed along with apt sheets....the topper is wonderful almost like sleeping on a cloud...but I use mine for the temperature it offers contained by the cold ohio winters here....so I am sandwiched near down on top and on bottom...LOL....Oh yes I keep the topper on year round even surrounded by the summer....but I also use the best cotton sheets too for a great nights sleep......I notably recommend the topper! But choose the down not its knock off imposters....