Hi guys!
First, it really doesn't matter how many PTC sites have you choosed to work with.
What matters is how you manage them...
First, ask yourself " How much time do I have? " and " Am I going to stick for long enaugh to get my Payout? "
After that... here's what you should be doing:
1. Join 10 PTC sites that has about the same amount of ads
2. Bookmark them with Ctrl+D and make folder "My PTC sites" or whatever you choose to call them
3. Open you bookmark menu and open you PTC folder by choosing "Open in All Tabs"
4. Login in into each of the sites and click the ads(I recommend to right-click it and open in "new window")
5. Close the ads after timer goes off
6. Rinse and Repeat
I have a slow PC and it takes about 30 seconds to open all ads from 10 PTC sites and about the same to close them.
So in just 10 minutes I finish all 10 PTC sites and have earned $1 dollar, which is pretty cool and it's only my personal efforts.
The problem is: It takes too long to get to the payout and then to wait for it...that's why you need referrals to speed it up.
If you look for active referrals, you should find a way to communicate with them and teach them how to keep they things organised ( the same I shared with you). This will increase your credibility and your referrals are more likely to stay with you, because you provide a real value.
How to communicate?
Well, you can set up a blog at blogger.com and make a guide with complete step-by-step PTC guide that your referrals can follow. Make it easier to digest with screenshots or better - make a video. It's easy to make a video if you have a microphone and screen recorder like camstudio.org . Making videos can be easier then writing

In you guide you should include your recommended PTC sites. It's very important to pick a respectable and paying sites that produces a real value. To help you with that, I recommend to look at PTCtalk . It's a site with PTC list that has been build based on people ratings.
Your guide should also include information on how they can get more referrals(the most asked question). It would be great Idea to explain them how you made this guide and how can they make the same guide too and attract more referrals. The key is to keep them organized so they don't run off to make their own guides and forget to actually click the ads and do the work because it takes time to build it up.
After that, you should focus on getting more traffic to your site. You will get natural traffic from search engines(like Google, the same you, probably, used to get here). Those people are looking for exact information you are providing so you got their full attention and if your site produces value(as it should be), you have made a new, active referral.
It's your job to welcome him and offer any help he needs. Also make a clear statement that he should take his time and go through the each and every step and do it on daily basis. It's the hardest part, but if you ask me, it won't be a problem if that person really, REALLY wants to make some extra cash. After all, It doesn't take more then hour a day to make a decent money after few month time from PTC sites. And these skills can be really useful whenever person decides to take "Earning Money Online" seriously.
This is the only way to get active referrals without risking to lose your "Hard Earned Money". Every single day there is about half of million people that use Internet for a first time in their life's and biggest percentage of them are looking for a Risk Free way to earn Extra cash online through the Major Search Engines and Social Networking Sites. It's a never ending stream of cash flowing to somebodies way....just make sure it's your way!

Cheers,
Andrew Levin(Cluviou4u)