I have a question about keywords. If I have multiple words in a phrase I want to use as a keyword AND have each individual word in the phrase as a keyword, "Vote Barack Obama" for example, do I need to put "Vote Barack Obama," "vote," "Barack," and "Obama" all as keywords, or can I used just the three single words?
I know this looks confusing. But if I had the three separate words as keywords, would they come up in any circumstance, or if somebody searches a phrase, would results only come up that have the exact phrase as a keyword?
I just want to make sure I'm not wasting key words by repeating phrases that would come up anyway with the single words.
There's an absolute science to this, and everyone's got a different opinion. If you want people to find you by doing a search for "Vote Barack Obama" then you are more likely to get hits if the text on your site reads exactly as that. That is not to say that a sentence which reads "Please go out and vote because Barack Obama needs to win" wouldn't also get hits, but you should aim to keep those phrases together as your main keyword. When you heard the term "keyword" that doesn't necessarily mean a single word; it can mean a phrase also.
Also make sure you are careful about repeating phrases too much. Do your SEO right and you won't need to.
Just use the three individual tags, separated by commas. The system doesn't handle phrases very well, and your ranking in search results is supposedly increased by fewer - more relevant - tags.
It's my understanding (but I'm frequently wrong) that a bunch of tags resulting in no popularity-boosts (purchases, cart-adds, whathaveyou) can negatively affect your position over time.