Anyone seen any results? Also how much do you vary the anchor text etc?
Question 2: I would think it depends upon the size of the order. If I order a bronze pack, I usually aim at 3 phrases. With a platinum pack, you might be able to aim at more. However, I'm sure you get the best results by using a narrow target.
Question 1: What do you mean by help?
I always see results. However, I do spend some time up front researching my key phrases. I doubt one firing of the trigger would rank a new site for keywords with lots of competition from older and strong sites. That would be magic.
However, I have had medium-competitive terms and brand new sites do very well. I have also used this service on a site of mine that is already strong, and it did gain the first page for a very competitive key phrase that I had been stuck on page 2 of Google for forever.
So, it will help you. It won't turn your brand new domain into a PR9. I might turn your brand new domain into a PR2 though. And I'm pretty sure it was mostly responsible for nudging a PR3 into a PR4. AND YES, I know PR doesn't really mean anything, but you get the idea....
And again, if I did an A+ job of research, instead of maybe only doing a B+ job, it might even help more.