Gaines, who helps develop marketing initiatives for her fiance's start-up, Wishcast, said she started using Pinterest for work, but when she got engaged in December, she created a new board for herself to gather and share wedding ideas with family and friends in Texas. She said she was surprised when distant friends and former coworkers started messaging her on Pinterest.
"I expected people to find out about [the engagement] through Facebook because that's where you go to make announcements," Gaines said. "But on Pinterest, I actually started getting messages from people saying, 'I saw your wedding board, congratulations.' I got several messages like that."
Pinterest, which launched in 2010, is rapidly growing. The site had 30.2 million unique users in January, according to comScore -- up 158 percent from a year ago.
Pinterest added a "secret" board feature last November, allowing users to keep up to three boards hidden from all of their followers or only share them privately with select users. The secret board setting would allow Daniels and Gaines to keep their secrets concealed until they were ready to reveal the board publically by turning the setting off.
While Pinterest declined to release any statistics about its users or their habits, site spokeswoman Annie Ta said "wedding" and "baby shower" are among the most popular search terms on Pinterest.
"There is definitely is a trend of people using [Pinterest] to plan these important moments in their lives," Ta said. "We see people planning all sorts of things on Pinterest, from their meal that night to their vacation in a few months to their wedding in a year."
Ta said it is hard for Pinterest to know for sure if people are revealing their big announcements with newly created boards before they tell people the news, but she said the site can reveal what users are thinking.
"You can look at a board and it tells you a lot about yourself and a lot about your friends based on the images they collect," she said. "[For example,] someone starts pinning for their wedding and they start to realize all of the things that they are pinning are a certain color scheme."
That can come with consequences too. Jacqueline Klingebiel, a 29-year-old projects manager for Homefront Communications, a Washington, D.C.-based strategic communications firm, jokingly said she developed a "love-hate" relationship with Pinterest when she started planning her wedding. While the site helped give her ideas, she said the pictures she found gave her "wedding envy." All of the do-it-yourself wedding projects she attempted added almost 30 percent to her wedding budget, she said, and an additional 300 hours of work.
"I would recommend any bride to not go on there," Klingebiel said, laughing. "You're looking at all these beautiful images, they look like dream, a perfect dream wedding ... [but] you have to remove yourself from the site and say, 'This is what in my budget is, this is what I can do and it is going to be OK if it doesn't look like these pictures.'"
Hayden said Pinterest has become so popular so fast because it is not as heavy and opinionated as other social media sites, like Facebook.
"It's where we share our dreams more so than any other site," she said. "So many things on Pinterest are positive and that is the reason, I think, it's so addictive... It's a wonderful, positive place to hang out."