And if I replace mine, do I need to shoot so often before it settles in?

I would say yearly, but it depends what type of bow it is and how many shots you put through it. Yes-most newwer strings require a "break-in" period of 200-300 shots to settle in.

i replace mine when it looks like it needs it. when the string starts to fray a little. i think every 2 years or so.

most strings do require a break in period, then you'll need to get things retuned, have your peep adjusted, etc... however, winners choice strings come pre stretched, and you don't really have the problem of the break in period. i just put a winners choice on my mathews and love it. i have shot a couple hundred arrows and no stretching thus far...just good groups

The above suggestions are good.
I would add, be certain to wax your string frequently and watch the timing on your cams.

I don't replace mine as often as I should, but I've never had any problems. A good quality string that is kept waxed usually last me 3 years easy.

Good Luck

Reloader

Replaced the string on my carp bow for the first time this year, bow was bought in 1992....

Im sure the string companies love you guys that replace them yearly. Course I normally only shoot 200-500 shots/year with that bow.

Do a search for Bucknasty strings on Archerytalk

I have one on my bow now for the last two years and right from the start performed great compared to the strings supplied from Bowtech

My bow is 11 years old and I have replaced it twice. I have also only shot it about 100 times a year since I have replaced the string 3 years ago.