Do you think that advertising in PTC websites helps your website/blog?

Of course in the form of impressions it helps a lot. This is the most cheapest option that i heard so far. You will get even one thousand visitors as low as for one dollar.

How ever do you think that these visitors are worthy ones? Intention of the members in ptc site are just to earn money. They will only stay in your site for the particular time in order to get the offered credit. They won't even get a chance to note your URL or wont able to read your website at all.

In particular if you advertise in PTC website to sell something, it would be a total loss, as you wont get any sales from it. You will only get impressions which was lasted for couple of seconds only.

Lastly if you have adsense in your blog, Google will block your account, stating you have violated the adsense policies.