Here are the results* from a 100-click solo ad I bought from Aleksandrs Meisars. You can find more reviews in my solo ad directory.
Clicks bought: 100
Clicks received: 119
Optin percentage: 43%
Cost Per Optin: $.45
You can find Aleksandrs at his website.
*These are the results from my squeeze page and sales funnel. Your results may vary from mine.