S-Builder Co-op is good if you are willing to wait for long time of your share and no fixed number of PSAs. While PSA To Go has a fixed number of PSAs to be delivered to you on the time stated by the TripleClicks in purchase. If want to immediately increase your PSAs, I think PSAs To Go is better. But remember you have to teach these PSAs to get them active in SFI. Of course both of S-Builder Co-op and PSAs To Go are good source of downline you need to make a strong team.