Publicly traded “lifestage” media company The Knot (NASDAQ: KNOT) announced today that it has acquired WedSnap, the developer of Weddingbook, the most popular wedding planning application on the Facebook Platform. Terms of the deal were not disclosed.

The acquisition comes only six weeks after Weddingbook was awarded a $250,000 grant through Facebook’s fbFund competition. fbFund, organized by Facebook, Founders Fund, and Accel Partners, deploys non-recourse grant capital and provides mentorship to entrepreneurs building on the Facebook Platform.

WedSnap’s strategy of focusing on building the best product for a highly valuable audience has apparently paid off. As of today, Weddingbook had 450,00 monthly active users doing things like seeking wedding advice from other brides, sharing wedding details and guest registries, and managing guest lists.

Shortly after the fbFund announcement, WedSnap CEO Kevin Lister spoke of perseverence and focusing on building products that users love:

We’ve been building Weddingbook for over a year. At times it’s been disheartening to see some spammy quiz application zoom past us in a matter of days. But we have a vision for what we want the product to be and we know that it will transform how people plan weddings. We’ve grown slowly and steadily and now have more monthly users than many of the applications we admired when we first started…

To create a successful application on Facebook, you can either build an app that takes advantage of the viral features of the platform or you can build an application that users love. I think it’s easier to build an application by exploiting the viral tools of the platform but easier to build a business by creating an application that users love. Of course if you’re really smart you’ll do both.

The Knot will add Weddingbook to its network of websites that serve “well over a million engaged couples each year.”

“With this acquisition, The Knot community broadens by branching into the fastest-growing social network of brides on Facebook, while Weddingbook members will have access to our extensive repertoire of tools, content, and vendor directories,” said The Knot CEO David Liu in a statement.

According to The Knot, the WedSnap team will stay in tact and continue to operate out of their Toronto offices.