Britney Spears' new video is just a commercial? And a young one has feelings about marrying before she's ready -

Wonder if her mom married before she had a job -

There's been some talk about the overt product placement in BRITNEY SPEARS' "Hold It Against Me" video . . . and it sounds like it was a lucrative move, because she supposedly raked in HALF-A-MILLION DOLLARS from it.

--The most obvious product placement in the video is for the dating site PlentyOfFish.com

--A so-called "source" says the site shelled out "six figures" to be featured . . . and it may have been worth it, because the site has had a 20% spike in traffic since the video premiered.