I’ve been building online businesses and e-commerce websites since 2000. I would never in my life start a new website with a “free” blogging or “free” website platform. If you do, within months your website is going to start growing, and you’re going to have to switch to a paid platform anyway. You will have thrown away all that time (and lost money in the process).
If you're serious about succeeding with your blog, you need to build useful anchor content. It needs to be engaging, keyword centric, insightful, unique and well written. Don't write your content for search engines. Rather, write your content for humans while also paying homage to search engines and what they want. Simply put, it's a skill that develops over time with practice. It's also important to regularly publish your content on a weekly basis.
Lets say, for example, that you refurbish and resell used smartphones out of your home. You could use a blog to attract visitors to your website where you list your current phones for sale. Your blog might cover topics about DIY refurbishing. On one level, it seems counterintuitive because you want people to buy your phones, but it also helps you build a brand and gain recognition. Social media guru Jay Baer explains the concept on Copyblogger: