Keyword help

I have been adding keywords to my files via File>File Info> and then entering keywords in the keywords box. I then have been 'Saving for the web' as a jpg file. When I go to open the saved file the keywords are gone. What am I doing wrong?
My goal is to increase my search engine organic rankings for the specific keywords. Is there a better way to go about it with images? Is it even worth doing for product images?
Thanks, Dan

Save For Web removes most of the file info in order to save space. If it is really important to you that your keywords are preserved, then use Save As to save the files. This will mean a slightly larger file but the keywords will remain after saving.