I'm trying to figure out which products are worth promoting and which are a waste of time. I've borrowed certain competition metrics from different sources in order to weigh the benefits of promoting one product over another. Here is the outline that I follow: I check the number of unique monthly searches for my keyword phrase of interest. If that number falls within a satisfactory range, I check the number of competing pages for that keyword. If that number falls within a satisfactory range, I check to see if any money has been spent on advertising for that keyword. If all things check out, I pull the trigger on promoting the product.
All this seems incredibly simple, but the real challenge lies in trying to determine an optimal range for both of my keyword criteria. What ranges would you consider optimal with regards to the number of monthly searches and the number of competing pages for a product? I understand that every situation is different, but any suggestions could be helpful. Thank you in advance.