In consumer marketing there is (generally) one person making the decision, in contrast to business marketing where there are usually multiple influencers – or even a buying group.  Someone initiates the purchase, others might do the legwork and make recommendations, and someone else ultimately decides whether or not to buy or what to buy.

In the case of Gen Y, they are unlikely to make decisions without parent’s input, especially for major decisions like investments, automobiles and housing. In this sense, Millennial purchase decisions can sometimes resemble a business-to business decision more than a consumer decision.

Here are three reasons why marketers need to consider the parents when targeting Millennials.

1. Parents may be underwriting the cost of the purchase, directly or indirectly.

According to a new Deloitte study of Gen Y and the automotive industry, one of every three Gen Y’ers who own or lease a car say they have a vehicle ‘my parents bought or leased for me’.  41% drive the same vehicle brand their parents drive now or have driven in the past.  This may have something to do with the fact that 40% still live with their parents or an older relative.  According to a study by Vibrant.com, 37% of Boomer women have an adult child living with them and 44% are helping a child or grandchild financially.  Financial dependency means Millennials are not entirely free to make their own big ticket decisions.

2. Millennials trust their parents’ advice.

Gen Y likes their parents, they get along.  Millennials have been relying on their parents for major decisions like picking a college and a major all their lives, so they aren’t going to stop now. An AARP survey on the financial state of Gen X and Gen Y found “70 percent of Gen Xers and Gen Yers look to their parents for personal finance advice and guidance.”

3. Millennials don’t entirely trust their own ability to make decisions.

Recently I posted that Millennials don’t feel entirely grown up.

Millennial blogger Blake Sunshine writes: “I do not feel like an adult. I support myself, have a job and live 818 miles away from my Mom and Dad, but I still feel like a child most every day. And I know I’m not the only one. Millennials everywhere are having a hard time growing up.” A corollary to not feeling grown up is not being ready to make grown up decisions. The AARP survey cited above says, while “86 percent of Gen Xers and Gen Yers know they should be more prepared for a “rainy day,” many report that they know more about their iPod (40 percent very knowledgeable) than they do about filing their taxes (26 percent), buying a home (21 percent), investing outside of work (15 percent) and saving for retirement (15 percent).

For Marketers, this means considering Millennials they way a B2B marketer might consider a business purchaser, with carefuly consideration to who is playing which roles, and the different needs of each target. Upfront research that involves recent decision-makers and their parents can provide extra illumination on the purchase process and how the ultimate decision is made.  In the car category, Millennials may be looking for something cool, and green with low gas mileage.  But their parents may have something else in mind. Knowing who will have the final say can mean the difference between sale and no sale. At minimum, it’s critical to give Gen Y the ammunition they need to make their parents feel they have done their homework and are making a sensible decision.

Universities have long understood this dynamic. Ask any college kid who made the decision about what college to attend and they will tell you it was their decision alone. Yet admissions officers know parents are critical at framing the consideration set, and often have the final say once it comes down to dollars and cents. Many universities start early in the junior year of high school with mailings targeting parents as much as teens.

For financial services and automotive marketers, a similar approach may prove worthwhile.