Instagram has passed Twitter to become marketers' third-most popular platform in social media advertising campaigns. Strata’s recent Advertising Agency Survey places Instagram behind only Facebook and YouTube.

Strata, an advertising media solutions and technology provider, found that 63 percent of advertisers plan on using Instagram in their campaigns, compared to 56 percent intending to use Twitter. This is the first time Instagram received more agency attention in Strata’s survey. Instagram’s position in the survey climbed 86 percent from last year, while Twitter slipped four percent. Facebook leads Strata’s findings by a clear margin at 96 percent, but Instagram is closing the gap with YouTube, with 67 percent of advertisers planning to use the site.

Social media spending is on the rise, with 17 percent of agencies saying they will allocate up to a quarter of their budgets on social, a 76-percent increase from last quarter. Social media also moved to the top for digital spending at 77 percent of agencies, a 28-percent increase over last quarter, to overtake display (73 percent).

“Digital publishers keep on getting better at providing more advertising opportunities to ad buyers,” says J.D. Miller, director at Strata. “Within digital, the fastest growth we’re seeing is in social media. In particular, it’s interesting to chart Instagram’s growth in agency interest. It’s no surprise that the social media ad space is getting more competitive as advertisers are given more options. However, along with social’s rise, video—both local and streaming—continues to dominate. Overall, agencies are getting a better handle on their media mix and are creating exciting campaigns with these various tools.”

Across all advertising media, TV remains the top choice for agencies. Strata reports that 48 percent are more focused on spot TV/cable advertising than any other medium, a 16-percent increase from last year. In its findings, spot TV saw a 19-percent increase in agency focus from a year ago, while cable TV saw a 24-percent increase.

Strata’s findings also point toward a healthy advertising market—49 percent more agencies project an increase in business in the second quarter over the same period last year, and 46 percent expect growth in the first half of the year to be better than the last half of 2015.