Hi Gokjoy,
This can be the danger of promoting a free chip but I would expect a few more signups.
I would say there is a higher number of downloads compared to those that actually signed up. Can you give me an insight into how you market, is it simply from your website or another method? (mail, ppc, forums etc.)
As Gregger mentioned try and look to sell the features of the casino more before the click, this way when the players sees it for real it will add value to both your site and your players experience.