I checked several free blog sites and I tried to use Simple Machine Forum and seemed to cause me to have error messages on my computer and unwanted pop-ups that I had not experienced before. Most free blog sites seem to offer the same affordances just laid out in different ways. I just went with Goggle Blogger. I have never viewed any blogs and I thought blogging would afford feedback and multiple communications similar to the Talk tab but that is not correct. Blogs allow individual to comment on anything really but most are on specific topics. According to Wikipedia a blog is a discussion or informational site published on W.W.W. and consisting of discrete entries (posts) typically displayed in reverse chronological order. A blog that uses primarily video to distribute insight is called a vlog. A glog uses pictures, drawings, and graphical communication.
I would use an online discussion forum for teaching the business concept of diminishing returns. I could have the students provide examples of the concept and how it has negative impact on a process or business. The class could select the top three examples to take deeper dive into. We could then apply the appropriate math tools to determine the best solution for the process. Technology tools such as graphic calculators and computers can be used to generate graphical representation of the outcomes.
Affordances can be used in examples such as adding salt to popcorn. Salt is good but too much salt is not. I believe most students can relate to the popcorn example. A more complex example or affordances could be fertilizer. Fertilizer is good to increase yield in crops but too much fertilizer causes harm to the crops. Then moving from these examples to higher order processes or business examples.