Jeff:
USPAP, 2002 edition, page 20, lines 702-710, paraphrased here for brevity:
.............analyze any current agreement of Sale, Option, or Listing of the property, if such information is available to the appraiser in the normal course of business.
.............analyze any prior sales of the property that occurred within the following minimum time periods:
.....one year for one to four family residential properties, and;
three years for all other property types;and
reconcile the quantity and quality of data available and analyzed within the approaches used and the applicability or suitability of the approaches used.
You should also be aware that there is a proposal to change the one year time frame and make a reporting period of three years for all property types.
Also, if you believe that noting past listing activity over a period of time provides information that is pertinent and or necessary to the present assignment, and it's exclusion might make the report misleading, then use that information. As an example, if the subject has been listed 5 times in the past 2 years, and did not sell, and now the owner wants to refinance at a higher value than the property would not sell for, I consider that information applicable to the present assignment.
I hope this helps in some small way.
BTW, using the phrase "USpoop" may be cute but it diminishes your credibility as a professional, and may cause a casual observer on this forum to believe that collectively appraisers are less than professional.
Don