Yea you may make a good impression. It's even possible your credentials are good and your resume stands out. But they don't have a job available right now.
So, how do you "keep in touch" without being annoying? When I was first starting out as a freelancer I just asked people, "How frequently would you like me to keep in touch?" and tried to keep to that schedule of phone calls and little notes with work samples. That worked pretty well for freelance work. But I haven't done that *cough* in a few years. And I haven't done that on this job hunt.
Thanks to the internet, I found this handy guide from a Toledo printer. It's essentially how to be of value to the people whose time you are taking up. See if you can't apply some of these ideas to what you're doing.
"76 Ways to Recontact Customers and Prospects"