removing commas from a line of text

who knows why it took me four times to get it correct:

echo "1,1,1,1,1,0,1,0,0,0,1,0,0,1,0,1,0,1,1,0,0,0,0,1,1,1,0,0,1,1,0,1,1,1,1,1,0,1,0,0,0,1,0,0,1,0,1,0,1,1,0,0,0,0,1,1,1,0,0,1,1,0" | sed 's/,//g'
which resulted in:
11111010001001010110000111001101111101000100101011000011100110