Another homework question: Why are some groups important but overlooked consumers both of advertising and products?

I’ve selected both mentally and physically handicapped groups to discuss. I’m having a bit of problem understanding the words “consumers of both advertising and products”. Does this mean there aren’t that many advertisements geared towards them? And not many products made for them?

My take on this is that the group has generally been shunned by society and regarded as not being able to afford the products they need.

Comments and advice, please? Thanks