My source is 'they' too.
18-34 year olds are getting started. Apartments, inexpensive cars, fast food, soft drinks. The working poor of any age spend this way, too. They are more likely to pay a hundred bucks a month on rent to own for two years rather than spring for an $800 TV. If they spring for $2,000 in furniture, they'll buy cheap so they can fill up more rooms. This is the demo that falls victim to check cashing companies and crappy low payment/high interest 'legitimate' predators. When the economy tanks, they'll trade their $7 Arbys meal for a $5 McDonalds meal.
25-54's are transitioning from getting started to slowly replacing what's wearing out with stuff that will last longer. They also have more established credit. They'll splurge on a $40,000 SUV if they are willing to keep the payments up. They'll start to buy homes and eat in nicer restaurants. They won't buy anything they don't need when the economy is in the toilet. This group is interested mostly in the nicest stuff they can get for the money. It's harder to gyp these people. Many of them wasted enough money by the time they were 30 to know where the traps are.
55+ is in the enjoying-their-grandkids stage. They're through putting their kids through school and helping them get started. These people have the most disposable income and travel most, buy RV's, etc. Once they hit genuine retirement, their spending will slow to a trickle. Their major expenses will be doctors, insurance, and taxes. Hopefully they have their homes and cars paid off.
The economy is starting to come back. Home sales, business openings, and nicer cars should start to sell again. If there's growth in demo money, it ought to be in 25-54 this year. That's where the most opportunity is, IMHO.