Forget it, if you are hoping someone (honest) will tell you to expect much links list traffic any more. Unless you want to climb on the script wagon and generate new sites every day (maybe even then), you need to generate your own traffic to produce sales.
- Differentiate between the SexKey (free) and Cyberage (recurring) models, because the first is arguably an easier sell but offers no recurring income and close to zero probability of upsells.
- Upsells-per-site on the recurring model are a small fraction of what they once were, courtesy of dilution of the links list by thousands of sites, changes in the rules and extra effort by the program operators to grab upsells for themselves.
Whether it is best to go free or recurring really depends on which you can market most effectively and on what you offer. If you can work a narrow niche well, recurring will likely pay off better and you have half a chance of seeing some upsells. Otherwise - and I wouldn't want to think what "a lot" might be in some categories - forget upsells unless you plan to build
a lot of sites. One or two will just get lost among the thousands already listed.