less then 1 satoshi is not problem
It is a problem because its not going to appear tangible or of tradable worth to anyone, not if the concept of less then 1 Bitcoin took years for people to realise you dont need an entire coin to really use it. Less then 1 satoshi is going to have the appearance of pocket fluff, I dont think its advisable to go this route when a gambling risk route can account for value adjustment and make it more fun for people to be involved with the site.
1 satoshi will not be a problem for a long period of time, people will get used to it. Think about it this way, freebitco.in is not getting this much customers because they are giving away a lot of coins, they are not actually freebitcoin, they are freesatoshi honestly and that is the difference, the reason why they are still going so strong is the people who gamble here and get free stuff with it, just the simplest version is, if you gamble on dice (hilo) here, you get lambo ticket and have a chance to win lambo, have lottery tickets for free and have a chance to win the lottery, and get reward points so you could get an iphone.
All of this because you gambled here. So, even if it is 1 satoshi or under, this place will be living greatly without a problem, people are not here for free money anymore, they are here because this is the place that gives the most profit for gambling, most of them are given even if you win while gambling.