I’ve come up with a system that works for me — I started a new Firefox profile specifically for PTC’ing, and have fifty sites bookmarked in groups of tens, which I open each group all at once in tabs (but I have to remember to only open one page requiring a login first, otherwise I get ten master password dialog boxes!) So I’m getting through all the sites I’ve signed up through Amber’s referral links fairly quickly now.
I’ve enabled the read emails option in many of the PTC sites that have them, but there doesn’t seem to be very many available for non-paying members. But I have done a few; some of them even let you read the emails from the internal email system at the site (I like that!)
I’m signed up with a few sites that do offers now too. I’m not sure I’m doing them correctly though — they’re very specific. I skip the ones requiring a credit card number or social security number though.
I’ve been looking at some survey sites too, but haven’t finished setting up accounts at the few I’ve signed up for (waiting for the confirmation email).
