People over 55 do not prefer Classic Rock to Oldies.
I wouldn't make a blanket statement to this effect. Some of us old guys enjoy a little Iron Butterfly, Cream, and album Doors cuts now and then. But overall I prefer a standard Oldies format. I find myself listening to Classic Rock at times, but I would say 75% of the time I'm camped on traditional oldies.
But, advertisers do not target radio buys to people over 55. So radio has no economic reason to cater to the over 55 demo.
It depends on how you sell the format. You can't sell Oldies the same way you sell talk, sports, or ChR. And when selling multiple stations the format will also get the shaft due to the contrast between it and other formats. I've never
seen a situation where a sales exec has sold Oldies in combination with other formats and the Oldies has not been the bastard child.
Case in point, our local cluster in town has a hard time selling the oldies station as they sell their whole cluster, so you get C&W, ChR, Metal, the AM syndie-talk, and the Oldies. So the Oldies station is tossed in at "added value", or the rates are cut because they are really selling the "other" stations. (Added to this is the fact that the station is dry, dull, and lacks good presentation and what motivation does a buyer have?)
However, that said, I do know stations and sales execs that have made good money off the format. The 50+ audience is a very loyal group if
they get a good format to listen to.
The key to good revenues on an oldies format is target selling, selecting businesses that are likely to sell to the 50+ M/F listener. Then, making sure that the format does provide the correct delivery, promotion, and news content that the listeners are looking for. And my pet-peeve; get the kid wannabe DJs off the station who don't know anything about the music, or can't talk up a song.
Anything worth working for, will return rewards.