But what if my keyword is more than the Tag limit of 20 characters? and yes, some of your keywords will be.

Two Scenarios

Scenario 1 - The keyword in question is your listing's primary keyword

Break them up to fit in your Tags. Even if the resulting Tags don't result in good keywords by themselves, you're looking at a bigger picture. Here's an example...

"Silver Starfish Necklace" - 24 Characters. 

Option A: Break it up to Tag 1: "Silver Starfish" (15), Tag 2: "Necklace" (8). 

OR 

Option B: Break it up to Tag 1: "Silver" (6), Tag 2: "Starfish Necklace" (17).

Scenario 2 - The keyword in question is not a primary keyword for your listing and isn't trying to match your title. 

Break them up to fit your tags. Try to make them keyword phrases shoppers will be searching (Marmalead will tell you that in the search tool!). This will broaden your reach with search when you put good keyword phrases in your tags. 

"Silver Starfish Charm Necklace" can become... 

"Silver Starfish" and "Charm Necklace" 

or

"Silver necklace" and "Starfish charm"

Did this answer your question?