A question about Harrington's Workbook

[Brewster]

He gives a sample hand in problem 11. Basically, there are a couple limpers in a pot, then it comes to you, with 44. You call the $200. Then the BB raises $2,700, making the pot $5,700. Everyone up to you folds. The question is do you call or fold?

Now, I would fold here, but Harrington recommends calling. He says that the reason for calling is that pot is giving almost 2-to-1 pot odds. What I don't understand is why that is so enticing. I thought the whole 'point' of playing low pairs was to try to hit a set, and since the chances of hitting a set on the flop are 1 in 8, don't you need 8:1 pot odds to call a raise like that?? Isn't that how pot odds work or do I totally have this concept wrong?