Here are the results* from a 100-click solo ad I bought from Bill Ulbrik. You can find more reviews in my solo ad directory.
Clicks bought: 100
Clicks received: 102
Optin percentage: 65%
% Tier 1: 66%
Cost Per Optin: $.58
You can buy a solo ad from Bill Ulbrik at his website
*These are the results from my squeeze page and sales funnel. Your results may vary from mine.