Boston-based ticket reseller CitySide Tickets is launching a national cable television advertising campaign this week in an effort to expand its business and challenge fellow Boston broker Ace Ticket. According to the Boston Herald, CitySide is planning to run more than 500 thirty-second ads over the next three weeks on cable news channels, such as Fox News and CNN. The eight-year-old company, founded by South Boston native Michael DeAmicis, is looking to raise its profile in major cities, including New York and Los Angeles. The cost of the ad campaign, which could reach a total of 8 million people, was not disclosed.