Learn then selling guidelines. Each marketplace has guidelines that define what you can and cannot sell. State and federal laws also impact what items are prohibited. In general, you cannot sell alcohol, weapons, service contracts, animals or event tickets. Also, while not always prohibited, you may find restrictions on how you can sell items in some categories, such as art, gift cards and coupons. eBay, Craigslist and Amazon publish these guidelines on their websites.
I have a personal blog that I use for journaling. I became good enough that I opened my own business as a social media consultant. I’m now making a decent amount of extra money. I am also a photographer with a lot of graphics program experience, so I make a little more by doing graphic design, photography, and even digital enhancement. You don’t have to be the best at something in order for it to be profitable; you just have to put in the work and be better or cheaper than other people out there. However, it IS work.
Donating plasma can actually work out better than selling your blood. It takes longer to donate plasma because they will put your red blood cells back in your system. The upside is that you can donate plasma as much as twice a week and you can make anywhere from $40-$60 per donation. You can make that $100 in less than a week if you can stomach the needle.