ROI calculation is very important in SEO like Long term process . Change of marketing strategies regularly works on Google .hows your experience ?
"Change of marketing strategies regularly" works everywhere coz marketing is an area where you need to come up with new ways to sell your information or product always
Changes of google algorithm is dramitically changed my whole website to down and I don't know what to do bring it up..
As always and works in most aspects of business and services, continuous improvement is very essential..
Keep updating and trying new activities always will never bring you down.With every change in google you also need to change the stretegies.