KeyWords in IndiBlogger

I am not talking about optimising keywords on your blogs but about the keywords that Indi asks us to mention for every new thread, new IndiVine submission to empower its search engine........ and I am not sure what other things need keywords. But they never show up anywhere, so do you really bother  to give keywords that match the topic of the thread or the IndiVine submission ? And what are the keywords you use most frequently: does --- fall under one of them as menioning keywords is compulsory and typing --- is much more easier than some big long word that really describes the topiuc of discussion ( I'm not sure if it is. I need to check it out)