My local Craigslist.org is the first place I go to sell something. It's best for items you think will appeal to everyone (therefore justifying the smaller audience) and large items that can't be shipped. Craigslist.org is great for taking your yard sale items online for local sales. For example, a friend recently bought two fans from people that live close to him. These one-off type items do very well on Craigslist. Just remember to use common sense and be safe out there.
These mega-sites make it easy to set up shop so customers can browse your products, and there's no need to build your own website. Also, you’ll find a built-in search feature so that interested buyers can easily find your online storefront. Plus, you get to use the site's shopping cart. In short, you avoid a lot of the expense and hassle of setting up an independent e-commerce website.
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.