If you are really interested in making money online without investment, you can consider affiliate marketing too. Affiliate marketing is the next step which you should take after blogging. In affiliate marketing, you will help the online e-commerce companies in selling their products by sharing the link of the product.
If anyone purchases anything via your affiliate link, you will get some commission from the e-commerce company as you helped in selling that product. Only, you just need a good website with sufficient traffic to sell products with Affiliate marketing.