The song peaked at number 16 on the Billboard Hot 100 and was certified double platinum by the Recording Industry Association of America (RIAA) on December 11, 2006.

[8] Due to the use of "I Don't Think So" in a promotional advertising for Big Brother Australia 2008, the song entered the Australian ARIA Singles Chart at number 49 on April 21, 2008.

[11] Ann Powers from the Los Angeles Times praised its eclectic music and said that it "mines a memory of R&B as the playground of category-dismantling individualists.

"[21] MSN Music's Robert Christgau gave Kelis Was Here a one-star honorable mention,[22] indicating "a worthy effort consumers attuned to its overriding aesthetic or individual vision may well like.

"[22] In a mixed review, Slant Magazine critic Preston Jones said that, although it is "an intriguing mishmash of sounds, beats, and vocal affectations", the album is "far too long" and lacks a song on-par with "Milkshake".

[17] Chris Salmon of The Guardian wrote that without the Neptunes, "contributors such as Black Eyed Peas' Will.i.am and [...] Shondrae reject all subtlety for songs that caricature Kelis as sexy, bolshy and not much else.

The results are shallow and unconvincing, driven by the kind of brash holler and breathy schmaltz you would expect from J-Lo or Pussycat Dolls (complete with the rubbish guest raps).