since 2008 the parking companies only allow type-in traffic or organic traffic from the major search engines, you always can blank the referrer which consider as type-in traffic or use any other blackhat technique to bring the user to type your domain at the address bar.
but dont forget, the good days of ppc arbitrage has gone, now the advertisers on the other side looking closer at the conversions and you need to deal with TQS -Traffic Quality Score etc....
Good Luck