Their riches seemingly had no outward effect on them as they related to other people. They were enjoying the riches God had allowed them to acquire but had not allowed the riches to enjoy them. This passage seems to need little explanation. It is negative to the end. Anyone wanting to be rich and acting on that desire, will fall into temptation, snares, lusts and these items will end in destruction and perdition.
Snare is simply the snare used to capture animals or birds.
The snare is something which acts totally unexpectedly. The prey is certainly startled and shocked at the snare because they did not know it was there, nor were they expecting it. The desire for riches will turn around and bite you very hard and very unexpectedly. The thought of destruction and perdition does not necessarily, but can mean eternal damnation. Personally I would assume that this is speaking of eternal damnation because most true believers would not fall into the downward spiral that is described here, but it certainly is an awesome warning for the believer - don't commit yourself to becoming rich.