• by Laurie Sullivan  @lauriesullivan, April 9, 2014

It will take "smart acquisitions" and innovative technologies to keep the interest of kids as they grow into adults, per a Piper Jaffray survey series of 7,500 teens.

The survey highlights long-term concerns for Facebook and other social sites that will need to compete with time spent on newcomers like Instagram and Vine. In its spring 2014 teen survey, the firm found that 30% ranked Instagram their most important social network, compared with Facebook at 23% and Twitter at 27%. A similar study done 1.5 years ago identifies that 12% of teens chose Instagram as the most important platform for them, compared with 42% for Facebook.

Interestingly, social-media sharing and metrics have become proxies for sales. Some stores are taking point-of-sale data at specific locations of one brand across multiple retail outlets and determining that those with higher social engagement lead to higher sales. During the MediaPost Social Media Summit Wednesday, panelists talked about L.A.-based Barney's Beanery. The store created a loyalty program that provides consumers with cash discounts in exchange for creating and sharing Instagram while in the store.

Brands don't have unlimited resources for paid social marketing. Marketers need to justify the budgets invested in campaigns. Many have begun to use surveys to validate how social impacts share in consumers' minds.

Piper Jaffray also analyzed trends around the Apple iWatch. Some 17% of teens suggest they are interested in an iWatch, up from 12% in an October 2013 survey. About 6% of teens own a smartwatch.

The Apple iPhone remains the most popular phone for teens. About 61% own them, up from 55% last fall. Some 67% expect their next phone to be an iPhone.

Sixty percent of teens said they own a tablet, with iPad representing 66% of tablet owners. Of those, 55% are iPad owners and 11% have the iPad Mini. The survey also reveals that 18% of non-tablet owners expect to buy a tablet in the next six months, with 49% expecting to purchase an iPad and 17% an iPad Mini.

When it comes to shopping, 31% of teens ranked Amazon as the preferred online shopping site, up from 23% a year ago. In fact, Amazon has steadily increased its lead as a teen favorite, per Piper Jaffray. The survey results rank Nike No. 2, pushing eBay down a notch to No. 3. Forever 21, Victoria's Secret, Eastbay and American Eagle follow.