My website sells many different products. I have already purchased directory link submissions and that along with artlicle marketing and social bookmarking has gotten certain keywords to rank well on google to rmain on top on google should I target keywords of products that I haven't use in the past or continue to target the ones that are doing well now.?
You should be targeting both..new as well as old...just increase the promotion of new ones at a more pace than existing ones!!
Since you are in sales of products it is better you put names of those in keywords. you can imagine users will go to google and type the product name often, so if it is there in keywords that is fine!!