Apart from all cloud mining being somewhat of a scam (As they rely on the altcoin prices to go up to make you a profit, and it that case you could have just bought the coins to start with and probably end up with more. . . )
But these 'free' hashes they give out wil only make a few cents a day most likely... And they seen as 'advertising cost' to the company as it will make you go to their site every day or two to see if its 'working' ,, that will perhaps intice you to buy more hashing from them.
Be careful and do not be tempted to buy any if you plan on trying to get free coins out of this. .
My friend used to do this and then send the coins out of faucets and free mining to dice games to gamble for free. Not sure he ever made anything tho or ever got lucky with this strat.