Makes 1 bitcoin in a month without investment? Maybe you can use a signature campaign to get bitcoin, but if you rely on a signature campaign is not enough. So you can try other ways such as selling services. If many who use your services you certainly can collect 1 bitcoin in a month.
Yeah, indeed signatures can help us to get more bitcoin. but to reach the target that we want will be very difficult for the signature to be able to give it, because we can get maximum signature in the bitcoin 0.2 BTC in a month. so in addition to the signatures we need to be able to do the other way so that 1 the BTC we can get within 1 month or 2 months, and it all takes a tremendous hard work to make it happen we want.
Currently just having some bitcoin or altcoin business might be the only way to get such income, besides those if you skilled you can work for others, but there are a lot competition online. For the people not able to develope some projects, you can try trading, signatures but its almost impossible to make you earn those, may you able to earn 0,15-0.30 btc, because 1 btc would mean a lucky investment and this doesnt happens all day some coins pump.