We have a 12 month old, a yellow lab and 2 cats - so I know a thing or two about stains.
I completely recommend the Hoover Steamvac. We had a spotbot, but it tended to only smear the stain into a circle. Then we bought the Steamvac a few months ago and the carpets look fantastic. It's super easy to use, and the carpets dry quickly. If you don't have wood floors, spend the extra $8 to buy the hard floor adaptor. Now I can use the same machine to wash the floors and the carpets.
The advantage of that over a service for the same price you still have it. The other day my daughter spilled a whole glass of cola on my light carpet and I just grabbed my steamvac and sucked it up. Then 2 cleaning passes and you can't even tell there was anything there.