Don't try out the PTC sites as they pay very less. With coinad, you can make around 0.001 BTC per month which isn't worth the time and energy and btcclicks does not have any high paying ads. Best is try to trade with bitcoins or earn them through giveaways, jobs in Service section or Signature campaigns.
PTC websites are only good and profitable for people who can gain a lot of "direct" referrals. other than that it is not worth the time.
honestly i think if someone wants to do PTC without direct reff. he should do faucets. they pay the same and without the hassle of loading different websites which might be scam or contain malware.