In our last post, "What Millennials Really Want From Your Brand," we covered the importance of convenience — making the shopping experience and messaging clear, simple and easy — in appealing to the millennial demographic. Today, we move to the necessary respect brands must have if they choose to engage with millennials on their coveted social networks, especially Facebook.

When Facebook started back in 2004, its sole purpose was to connect friends online, but now brands and businesses play a big role in shaping user experience on the site. Regardless, millennials love Facebook more than ever: Over 80 percent of them use the social network, according to a 2011 Harvard University study.

Yet, millennials are wary of engaging with brands on Facebook, as they fear being harassed or spammed by them. Many in Gen Y want to interact with brands on their own terms. Below are telling things millennials told Parham Santana about brands and social media use:

• “If I like something I want to pick how much involvement I have with it rather than having them give me something I mostly don’t want.”

• “A year ago, I said keep it only friends. Now, I’m still on the fence about [liking brands]. I don’t want my Facebook to get spam-y.”

• “Brands that interact with people on Facebook and Twitter are really cool and appealing to me. It’s cool to think that in this big company there is someone who is taking an interest in what the consumers want.”

• “I don’t follow any brands on Facebook. I guess because I don’t want Facebook to get too familiar. When the ads on the side don’t interest me, I feel like I’ve won.”

• “I don’t like brands on Twitter and Facebook. I don’t want my feed getting mucked up with advertising. I don’t think brands have anything interesting to say. I’m not going to choose to watch advertisements… they already put them on the side of the screen.”

To win on Facebook, brands must master the concept of the social networking personal bubble by balancing quality versus quantity. Millennials consider too much of anything annoying, especially when it’s a brand interrupting a mostly personal Facebook stream. They’re most likely to respond to authentic, compelling content from brands in small doses.

Sylvan Lane, 18, of Mohegan Lake, N.Y., says Jimmy John’s gets it right. The sandwich company approaches its social media feeds with the same wit and humor on display in its ad campaigns. A recent post, for instance, read “Make up a song about National Sandwich Month to the tune of ‘Call Me Maybe’. Ready, Go.”  It received more than 200 likes and nearly 200 comments.

The brand’s Facebook posts reflect the brand image. Posts are short to mimic Jimmy John’s lightning fast service, and there’s rarely more than one a day. Every post engages the customer and has a purpose—whether it’s to prompt a laugh or advertise a sale.

But not all brands’ social media pages are as successful as Jimmy John’s. “One thing I’m not crazy about is sports websites like SportsNation doing the ‘Like if you think Phelps will win gold and share if you disagree.’ I just think there are better ways of starting a discussion about a sports topic and getting your brand out there,” Lane said.

Users want opportunities to be creative, voice opinions and share stories. The SportsNation fan gains nothing from liking or sharing a photo — this type of a post is intrusive to news feeds and acts as spam.

Key insight: Offer an interactive, personal and insightful social media experience to attract millennials. A boring, spam-like and intrusive experience will drive them away.

[BIO] Ross Gordon is a marketing intern at Parham Santana and majoring in journalism at Northwestern University. At Northwestern, he is the managing editor of the Northwestern Business Review, project director at Form & Function Marketing and philanthropy co-chair of his fraternity.