I use Paid to sign ups and it works for me. Only be carefull where you buy the paid to sign up. I can recommend OpalMail. Not too expensive and the PO is cooperative.
I would not focus on new programs. In stead I only build on programs that paid me, or seem to be very honest.
So you see, many persons , all different advices:
Just consider: What kind of person are you?
(Carefull, or ready to take a gamble.)
How much you want to make and how long do you want to continue clicking emails. The first period might not be rewarding, but cashflow will start later.( after a few months)
Also, how much do you want to invest? Will you use your own money, all your earnings or part of your earnings?
You can also try Ebay offers , some are very expensive but there are some bargains sometimes. Just watch them and try to pick the best. Also wait with Bidding as longis possible( best time is 1 minute before the auction closes.
I hope this helps