The big comma versus no comma question with meta keywords tag. Do you use a comma to separate them or not? A thread at WebmasterWorld named Does Yahoo Prefer Meta Keywords with Commas? discusses the case with Yahoo! We all know Yahoo! does look at the meta keyword but places very little weight to the meta tags when ranking a page. According to the thread, you should separate your keyword phrases with commas.
I guess there's going to be a feeding frenzy on meta tags again, which is going to be quite interesting [laughs] And just when I thought it was safe to bury the meta tags issue! Anyway, for the purpose of getting the facts: how many keywords do you put in a meta keywords tag before you start to flag yourself up as spamming?
Okay here's a couple of parameters. Each keyword is an individual token separated by commas. So that's that. You want to separate these things with commas and not just put one long string of text. The more keywords that are put in and the more they're repeated, the much larger the chance our spam team is going to want to check out that page. It doesn't mean that page is going to get any specific judgement. But it is very much a red flag. For best practice you just need to remember it's for matching - not ranking. Repeating the same word 20 times is only going to raise a red flag... It doesn't increase your likelihood of showing up on any given set of search results. It's just a risk with no benefit.
So I could put, I don't know... er... for instance, ‘laptop computers, desktop computers, palm computers...’
Exactly, and, of course, since each of those is separated by commas, then ‘laptop computers’ will count for ‘laptop computers’ and not ‘laptop’ or ‘computers’ separately. So doing it like that means that you're not going to be penalised for keyword spamming on the word ‘computers’.
Forum discussion at WebmasterWorld.