bitcoin is famous,we have number sites to earn bitcoins without investment.we can search in internet.gambling sites also there.bitcoin is famous so number of sites using this bitcoin for fake.but take care while searching that sites.but i dnt know how is it possible.if it gives bitcoins it is super opportunity to all.if it is free of cost we can try this.
One of the major problems with such sites is that to earn free btc it will take away all your time and you get hardly any btc instead of spending that time on such sites, I will prefer to invest in learning or developing some skills so that it can be used elsewhere and get better returns than on such sites. Instead you can earn though signature campaigns, do freelancing work and get paid in btc or you can invest in altcoins and get good returns if you select the right coin for future.