You can sell something on online shopping sites.But you need time to do all this stuff and you should invest your time.

You should join the campaign. Maybe it will help you to earn Bitcoin through the campaign. However, you need to invest some time and effort to accomplish your tasks. Besides, you must have knowledge and understanding of Bitcoin and some other technical currencies. During the writing process, I believe you will learn a lot more things that will be needed in the near future

For now bounty campaign - signature campaign is my only way to get bitcoin without investment i want to earn a lot of altcoins someday and i want to learn all about in trading becuase my friend says trading will give me more profit.

Yeah the joining of the campaigns is now very common a lot of the people are making money even they do not spent anything it is just because they joined the signature campaign, it is very easy to write the post and the profit will be slow but it will be constant, it will not be slow but it will give the high more than the jobs income.

The price is so high now that it's not going to be easy without any kind of investment, since people no longer give them away, no faucets etc.

The only ways i can think of really are freelancing, coding, design, offering some kind of service in exchange for bitcoin. I mean some people on the net do tip bitcoin, albeit very tiny amounts, or at least they used to..

Edit: the only other ways i can think of is selling physical goods or virtual products. Also working on projects part of a team etc.

Few ways would be -

1) Sell services and get paid in btc.
2) Participate in bounty programs on bitcointalk, etc and exchange those Alt coins into btc.

There are many ways to earn bitcoin without investment. I think the best way is to offer your services and ask for bitcoin as payment. You may have skills in graphic desgning, proofreading, tutoring, or web designing or any skills you have that may appeal to your future client may be used as your way of offering your services. You may also try the faucets that give very small amount of bitcoin (satoshi). This may take time but you can try this in your free time. If you feel lucky, you can try some lottery like games. You just have to watch videos or solve captchas then you can have entries for the raffle. And of course, you can post to forums specially here, and eventually you can earn substantial amount of bitcoin.

Don't try to spend your time on faucets, there are a waste of time. If you really don't want to invest even a single penny then try bounty campaings, you will earn a little. With that money you can make small profits on trading and after that you can order ASIC miners to mine directly Bitcoin. It will take you a lot of time, maybe even a year or more but it's nothing amazing if you don't want to invest anything.

if you don't want to invest with money, you might as well invest your time in accumulating bitcoins. The most basic and easiest way to do it is joining signature campaign here at bitcoin talk. Although it is really not that easy to join signature campaign these time due to lot of competition and this is good because when you are just posting quality comments, signature campaign manager will prefer you over other applicants.

Reality should not be ignored in any case. It is not possible for a new person to get start from mining in the field of bitcoin because mining is much difficult, time consuming and expensive process. I don’t think so that someone can earn bitcoin without investment/trading in bitcoin but if someone suggest signature campaign for earning bitcoin which also time consuming and in a sense they are not to have a business in the field of bitcoin.