Doing surveys is another good idea. Do one that is useful, amusing but is in some way related to your products. This often generates coverage and can elevate you to the position of 'market expert' which is exactly what you want.
Once a journalist has had a couple of good articles from you it is likely they will remember you. It is worth saying to them that if they ever need a correspondent on certain issues you would be happy to oblige. Just remember what you are an expert in too. Our recycling
entrepreneur above is at least an expert in:
* local business
* family business
* growing business
* recycling
* the environment
...and could well be expert in...
* haulage
* landfill issues
* international trade
Remember though that if you are going to say you will help a journalist, you must do so if they do call on you. They don't like being messed about as much as you don't. Biting the hand that feeds is not a good idea!
If you are still struggling for an idea give away a free lunch, have an open evening, let people come to your centre free for a day, do something really genuinely bonkers. Not 10% off. Free - give it away! Although there is a cost associated with this because it is free the paper/publication will be more likely to print your phone number or website address. Be aware though that this is a dangerous game. You still might not get coverage and if you do you might get inundated so think about a limit to the offer!