The sandbox thread has been plaguing SEO firms, I am pretty sure this site was the first to report on this theory back in April. A thread at WebmasterWorld named Telling Customers about Time it takes to Rank discusses how SEO firms are handling the task of explaining why its taking so long for their new sites to rank well. The first post is kind of funny, so I will quote a piece of it below. The thread then goes into people's experience with the sandbox, so it goes way off topic as to the original post, but the first post is worth reading if you want to get an idea of what SEO firms are saying.
Here are a few comments I have made to customers recently:
1) "Honestly, it is going to be at least a year for you to see any decent results unless you purchase Google Adwords. Google is pretty much a Pay Per Click search engine now, unless you've been around for a year or more." 2) "I realize it has been 6 months and you have spent over $20,000 on your site. Unfortunately, no amount of money is going to make you rank in the "pure" results. I sincerely apologize for telling you that I thought it would be 2-3 months. I was wrong." 3) "You are asking when your site will start making money? I have no clue, because there is this mysterious "sandbox effect" going on at Google. I know my answer sounds like "smoke and mirrors", but I mean this sincerely, and I don't know how long it will take for things to change." 4) "I'm very disappointed that you have decided to stop using my services and instead are now using spamtheseachengines.com. I've tried to market your site using knowledge I've gained with over 6 years of experience, and unfortunately there is a major delay in seeing the results that I expected. I still believe you are going to benefit, even though spamthesearchengines.com is going to get all the credit."