Believing in Walt Disney's (NYSE: DIS) new ESPN streaming service -- ESPN+ -- just got easier for investors. Only about five months after the new service's debut, it has garnered more than one million paid subscribers. This is an impressive achievement when considering that the service is an add-on to traditional ESPN programming.The achievement bodes well not only for ESPN+ but also for the company's overall efforts to transition to a multiscreen, streaming-based TV era.ESPN+.