That's an interesting statement. If you look at the home page you will see that 29 of the 30 reviews displayed are from May or June 2011. The 30th is from April 2011--still a far cry from 6 months old. Now if you are calling up and looking at individual listings for campgrounds it is very possible that you are seeing reviews that old. If so it is because no one has submitted a newer review for that place. I have seen some campgrounds in the database that do not have a review since 2009 or farther back, but again, that is because we have not gotten a more recent one. We post all reviews (that meet our guidelines). Normally new reviews are posted in 1-2 days. We sometimes get a little farther behind in the summer when we get over 100 reviews a day. It is hard to keep up with that amount, but even so they are usually posted within a week. Hope that explains things a bit.
To add to what TX has already said: It is also possible that the reviews the OP is looking at are for parks that are closed or don't do much business over the winter months. This would include most of the northeast, midwest, and mountain states. These parks do 90% of their business between Memorial Day and Labor Day (and most of that between late June and late Auust when the kids are ourt of school) and it would be unusual to have many 2011 reviews this early in the season. Additionally, early season (May or early June) reviews for these parks can be a bit unreliable because that they often do not reflect what the park is like in peak season (July or August). For example, all the amenities may not be up and running in May or the park may be quiet and roomy in early June before the vactioners start to fill it up in July.