Some tips you might don't know.
Very important factor is Google TrustRank.
1. google check Whois. Register your domain for min. 10 years. Google don't trust when domain registered only for 1 year.
2. Contact information and privacy page! It is very important to have names, e-mail, adress, phone, fax on your contact page. Google trust this sites more.
3. Use only unique contest.
4. Try to apply for all top programs and awards.
www.alexa.com - Good review and 5 stars.
www.mcafee.com - your site should have green siteadvisor rank.