about PTRs,ptcs etc

Tweet

I have seen quite a number of posts promoting one ptc,pts,ptr etc or the other here on mylot,one thing is these they are all always free to join but the catch will aklways be upgrading to get more ads to click to earn more,now i want to know is there anyone here on mylot who has upgraded membership with any of these sites and do you think the amount spent upgrading is worth it when you consider your earnings after the upgrade?