They are not my friends or family. These are normal people brought in through adwords PPC. Paid $500 , received 350 visits, 168 became simple members, 26 registered for a free trial, 19 autoenrolled for 70Usd/year, the rest canceled. For me this is relevant because I got my money back. I can pursue existing members to share and get me their friends in exchange of 1-2 months free. Would these numbers be relevant for an investor ? Should I keep on doing it and see if the numbers stack up or if it was a lucky streak?
I would do another test run to confirm that it wasn't a one-time lucky streak that you hit. These numbers are definitely relevant to investors as they want to know the conversion rates. You should calculate your Customer Acquisition costs as this number will be important to investors. However, looking at your numbers your model seems to be working just fine.