If you have a free strategy you want to share, showing it off on one or more of the MT4 sharing sites isn't a bad idea.
Be aware that many of these sites allow one of two things. Some let a trader upload a statement that may have been modified. Others pull the information from the broker, but allow the trader to filter it either by changing the start date and/or by some other means (comments on trades, currency pairs, etc). This means that the information displayed on those sites may or may not be complete and accurate.