Kayak’s first quarter profit fell more than 48%, compared with a year earlier, as the travel metasearch company increased its stocked-based compensation, and spending on brand and online marketing.

Kayak filed its results with the Securities and Exchange Commission yesterday, and it could be the final time such detail is publicized as Priceline’s $1.8 billion acquisition of Kayak is expected to close, after much delay, May 21.

Kayak’s net income in the first quarter fell 48.6% to $2.1 million as revenue rose 12.1% to $82.3 million, compared with the first quarter of 2012.

What changed?

Stock-based compensation soared 64.5% to $4.9 million, brand marketing for all of those commercials jumped 13.8% to $23.8 million, and online marketing/keyword purchases for i Kayak, and its Swoodoo and CheckFelix units climbed 31.9% to $24 million in the first quarter.

Of course, Kayak’s symetrical $23.8 million and $24 million spend on brand and online marketing, respectively, is just a proverbial drop in the bucket when measured against the $27.7 million and $403.1 million that soon-to-be parent Priceline shelled out on offline and online advertising in the first quarter.

That’s a big advertising piggybank that Kayak could benefit from.

For the quarter, Kayak saw its queries rise 18.1% to 358 million, and downloads of its apps increased 17% to 3 million.