Westlake Village-based ValueClick said this morning that it has launched into the health and wellness market with a new online advertising network. According to ValueClick, it has created AdRx Media, which includes more than 50 online health and wellness information sites. The new ad network includes sites like Britannica Health, HealthGrades, Healthy.net, Merriam-Webster Medical Dictionary, and more, with what ValueClick said has a "potential reach" of more than 20 million unique visitors per month. The new advertising network will be part of ValueClick's Media division.