I mean they normally didn't even do 10 days, they were around 9ish days period, a bit over but still less than full on 10 days 240 hours. By the looks of it people actually starting to go outside has hurt windice more than we have imagined, or maybe it is something else, could be the 1/10 level rewards they are giving out right now that has changed so much? I don't know the reason but decline is obvious.
Now maybe windice has a huge customer base compared to before but the new ones just don't play that much or there are now bigger whales who play less in count but more in wagering amount. I don't know what could be the reason but all in all you can't deny that around 1.5 million bets per day versus 13 days for 10 million is a big difference and even though its still fine, I would have expected a lot faster by now since it used to get faster and faster.
No one cant say it is a true fall except the owner who knows the exact condition on the site. Having slower increasing number of bets does not mean that windice get less profit. The lack of promotions can be one of the reason why it gets less bets lately while on other side, most other sites are offering regular promotion daily, weekly and monthly. In general there will be always a change on any sites regarding the number of bets. It cant be something stable, sometime it may take shorter time but sometime it may take longer time for every million bet.