Here is another link about the voting between these two software:
http://www.lastcombat.com/BitDefender_vs_Kaspersky.html
You may have a look
BitDefender is an antivirus software suite developed by Bucharest-based software company SOFTWIN. It was launched in November 2001, and is currently in its eleventh version. BitDefender replaced SOFTWIN's earlier AVX (AntiVirus eXpert) product range. The BitDefender group spins off from SOFTWIN in 2007. The BitDefender range includes antivirus products for home users, businesses, enterprise users and Internet service providers. Home editions support Microsoft Windows, Symbian OS and Windows Mobile; business and enterprise editions support Microsoft Windows, Linux and FreeBSD. The current version of the Home/Home Office security suite includes antivirus, anti-spyware, firewall, e-mail spam filtering, backup, tune-up and parental control components. A free basic online scan is offered via the BitDefender website.
Kaspersky Lab (pronounced /kæsˈpɝski læb/) is a computer security company, co-founded by Natalia Kaspersky and Eugene Kaspersky in 1997, offering antivirus, anti-spyware, anti-spam, and anti-intrusion products. Kaspersky Lab is a privately held company headquartered in Moscow, Russia with regional offices in Germany, France, the Netherlands, the UK, Poland, Romania, Japan, China, Korea and the USA.