Does anyone know the reason we don't use commas to separate keywords? Seems that that creates duplication and eliminates the opportunity to use phrases. For example, instead of animal products, pet products, fish products, I can only use fish, products, amimals and pets. I don't get to add these phrases. So only very general terms can be used it seems. Comments anyone?

For Yahoo!, this is what Jon Glick, Senior Manager for Web Search had to say (paraphrased):

Yahoo! uses the keyword tag more for matching than ranking. He says that keywords should be separated with commas. He suggests using them this way: laptop computers,desktop computers,palm computers. Using it this way means you won't be penalized for spamming with the word 'computers'. This would be spamming: laptop,computers,desktop,computers,palm,computers. He suggests to also use the keyword tag for synonyms and common misspellings of your keywords - like the old days.

Side note: He had this to say about the description tag (paraphrasing) -- Yahoo! indexes the meta description tag and it counts similar to body text. This is another good reason to have custom description tags on product pages.

A really long list would be a red flag. Assuming your keyword tags are specific to each page, the list shouldn't be all that long.

About the comma thing - I get the impression that it would be better to not use the keywords tag at all if you cannot separate the keywords with commas, and commas only. When separated by commas, each keyword or phrase is an individual token. With spaces, it's just a long string of text and another red flag.

Now that I'm TOTALLY confused on whether or not to use commas, no commas, commas with spaces after them, commas with no spaces after them...
What is the consensus around here???
Also, what is the maximum number of keywords for a category that we should be using?
Dan Kennedy or Ryan, do you have any thoughts on this confusion???
Just when I go and CHANGE STUFF, another thread starts with the comma thing...
I'm wondering if this has anything to do with why our serps are terrible!
Thanks again,
Ben N

Ben N, I'm right with you! I'm SO confused about how to specify keywords. A definitive answer would sure be nice!

This is just me, but when a search engine exec makes statements like this, I tend to believe he knows what he's talking about. If the Senior Manager for Yahoo! Web Search doesn't know what his search engine is looking for, then nobody knows.

Commas define the parameters used in the matching equation. They define keywords and keyphrases as independent variables. If there are no commas, there are no specified variables or values and nothing to consider.

Thanks again for the responses.
I guess I'll give it a test run on a few of our main categories.
I'm going to try keywords WITH commas and NO spaces, like this:
George Foreman Grills,George Foreman Rotisseries,George Foreman Cookbooks
Ben N

PS: Still confused as to which engines & spiders like what foods though...

It seems that the advantage for using it at this point is for synonyms and common misspellings. For example, if Foreman is commonly misspelled as 'Forman', you should put it in your keywords tag. Think about synonyms you can use too.

Yes exactly. I have as many synonyms as I can think of (bbq,barbecue,barbeque) in there.
I also included the most frequently misspelled words too.
How many keywords/key phrases is too many though???
Thx,
Ben N