This is how those free bitcoin opportunities are working. They come and give some free giveaways and from that they do get some traffic out of you. Then they will close the business with profits or do this just for some attempts. That's all. You cannot get an all time consistent income ways from free bitcoins sources. (There may be some exceptions but I'm talking in general).

Just look for rewards for your hard work that is the only way to earn bitcoins. Free never gives enough reward for your time and hard works.