A couple of weeks back, when the bids and offers were a bit...

A couple of weeks back, when the bids and offers were a bit thin, I dropped a sell order in of 3000 shares 3c above the current bid. Within a couple of minutes I'd been taken out (fresh meat on the menu). I waited about ten minutes or so and dropped another order in of 2000, same deal 3c higher than current bid, went and made a coffee and when I came back that had gone too.
Not sure how many bids and offers are real and there are plenty of 'gap fillers' in there at each .005c level. Who does that? Not retail investors