This was a good year for social networks. If a study by eMarketer is correct, 2008 will be even better. A MediaPost Publications article displays eMarketer's results, showing that ad spending on online social networks will nearly double to $2.2 billion in 2008. That's up from $1.2 billion this year. MySpace and Facebook claim about 70 percent of ad dollars. "The continued growth of social networking seems assured unless teens stop social networking as they become adults," said eMarketer senior analyst Debra Aho Williamson in a statement.