I didn't work enough at developing a blog to see any results when I had my firm. This points up the fact that it is a long range project. The sooner you start the sooner you get results. My first blogs were on Blogger and later Tumblr. I was attracted to the 'free' part of the equation. Both are good blogging platforms. Blogger, a Google offering, lends itself a bit more to text and has more features. Tumblr shows off photos better, which I think the many users of Tumblr would agree with. WordPress, which I have not used, seems to be very popular these days, so it's worth investigating. They all work a lot like developing a website - pick a theme that will control fonts, colors, and organization of the page, then start adding content. It is pretty easy. Of course, a service like Weebly* includes a blog, which makes the integration tighter. However you can always link to your third-party blog in your menu system if blogging isn't part of your website's capabilities.
A blog gives you a way to bring folks back to your site and it gives folks a reason to return. I think it is pretty hard to convince a prospective client of your value with just one visit. With a blog your site becomes like an advertisement that builds your brand through repetition.
Another advantage of a blog is that Search Engine Optimization [SEO], which is difficult to begin with, is even more difficult with a static website. People searching for information on a topic are more likely to find your information on that topic if you have a wealth of content. Every blog post creates another page and another opportunity to mention the keywords that you want to be identified with.
But the main reason to have a blog is to draw people back over and over to see what's new in your "brochure".
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