There are many social media campaign around. If you like, you can join them and earn money from tweet and retweet. Try to apply in one campaign to test and if you have experience already, you can apply upto 10 campaign at a time 
Yes, you only need to be aware with their rules or else you will be forfeited in that campaign . Watchout for updates so you wont blame them if you dont know if theres a changes.