...is that your opponent(s) have a pretty good idea of what you have right off the bat, and you add very little value to the pot - it would be a much better idea to open-raise!  Your  opponent still has a decent idea of what you hold, but at least you get an extra small bet in the pot this way from each person who decides to play against you.

PokerStars Home Game #57611998754: {7-High Poker Club} Tournament #364228095, $1.00+$0.10 USD HORSE (Razz Limit) - Level III (40/80) - 2011/02/13 15:13:49 ET
Table '364228095 1' 8-max
Seat 2: k06mars (4030 in chips)
Seat 4: garysroom (1970 in chips)
garysroom: posts the ante 8
k06mars: posts the ante 8
*** 3rd STREET ***
Dealt to k06mars [3h]
Dealt to garysroom [7c]
garysroom: bets 40
k06mars: raises 40 to 80
garysroom: calls 40
*** 4th STREET ***
Dealt to k06mars [3h] [Ac]
Dealt to garysroom [7c] [2h]
k06mars: bets 40
garysroom: calls 40
*** 5th STREET ***
Dealt to k06mars [3h Ac] [Qh]
Dealt to garysroom [7c 2h] [Ad]
garysroom: bets 80
k06mars: raises 80 to 160
garysroom: calls 80
*** 6th STREET ***
Dealt to k06mars [3h Ac Qh] [7h]
Dealt to garysroom [7c 2h Ad]

garysroom: bets 80 k06mars said, "i know you paired either your ace or two.." k06mars said, "" k06mars: raises 80 to 160 garysroom: calls 80 *** RIVER *** Dealt to k06mars [3h Ac Qh 7h] [As] garysroom: checks k06mars: bets 80 garysroom: calls 80 *** SHOW DOWN *** k06mars: shows [4h 8h 3h Ac Qh 7h As] (Lo: 8,7,4,3,A) garysroom: mucks hand k06mars collected 1056 from pot *** SUMMARY *** Total pot 1056 | Rake 0 Seat 2: k06mars showed [4h 8h 3h Ac Qh 7h As] and won (1056) with Lo: 8,7,4,3,A Seat 4: garysroom mucked [3c 2s 7c 2h Ad Td 7d]