You can grow btc by alot of different things. A good thing to do are forum signature campaigns which earns you money per post you post.
You need a good forum rank though to earn an okay amount but it's very easy go check it out, goodluck.
But participating is signature campaign is not a way to get a higher amount of bitcoins as the earning from there is limited and we cannot become rich with or cannot get bitcoin with which we can spend a luxurious life. If someone want a high amount of profit and want to get a big amount of bitcoins in short time then you have to invest them.