Absolutely!

We always deliver our Image Ads with keywords (search
words) embedded into the code that is copy/pasted into
the body of your ad. Without these keywords, your ad
would never come up on a user's search - all
the words in your ad are contained in
the image, not text that Craigslist
could index.

Examine the code we supplied with
your ad. Several lines from the
bottom, you will see many keywords
already in place. Edit these if you
wish with a text editor, then re-post
your ad.

Click here for more info on these invisible keywords.