sorry, you probably don't want to hear this, but you have to up your game a bit to get more downloads:
- shoot more commercial images, images you have in your port often lack concept. what do they represent, what do they sell? that armadillo toy, for example: how often there is a need for an armadillo toy picture? one sale in thousand? one sale in million?
- hire models or persuade people in your surroundings to pose for you. cast them. use those who have commercial qualities. young, pretty, well dressed men and women with perfect skin, teeth, hair etc... doing usable commercial lifestyle things sell. your people images compete with them. you probably live in an area (US,UK, Canada or Aussie) where finding ethnically diverse models is not such a problem. Where I live, in South-Eastern Europe, for example, it's 99% caucasian, so I can't find models to catter to that market.
- try to compete with other images of the same type. those notebooks and pencils look nice, BUT they are not noticeable among thousands of shots of notebooks and pencils that look better. better isolations, brighter images, cleaner paper, better arrangements, color harmony etc etc.
I have entered the stock game too late. in June last year IS had photos numbered with 6xxxxxx, now, just 1 year later it is into 10xxxxxx. 4 millions of pictures (not all accepted offcourse, but at least one third is) more in just a year. that means that one smiling businesswoman that used to sell hundred times in 2007 is now getting at best 10 or so dls. and the market is shrinking. I really HOPE someone will break this argument, but I'm afraid it is so. Riding the best match search engine train (pure luck) with the best image you can afford to make (not luck, it's solely in your hands) is the key to getting those flames to pay for the costs of the production and make some profit at the end of the day.
hope this helps, if not, sorry.