I bought my rubber plant a couple months ago. I have it in a room that receives bright afternoon light - the window across the room is southwest-facing.
When I bought the plant it was quite full but has since lost most of its leaves. The top has good new growth but almost all the bottom leaves have dropped off. Since I took the below photo a week ago, all the leaves have fallen off the bottom limb.
The leaves have brown spots as shown here:
Could it be that it's not getting enough light? Could it be pests? I have only watered it twice since I got it so I highly doubt it's getting too much water.