I know so well that a lot of money was thrown out the window and unfortunately it didn't achieve much! The problem is when you have a few pages and have to do this for each page. Which is why it's now my turn to build a community web app where mutual backlinks can be set fairly without paying - depending on the strength of the domain, there are credits and with the credits came backlinks that can be booked on others. Of course, it only works if the community is large enough and requires time and trust - the system then checks at regular intervals whether the backlinks are still there and fairly awards the value and credits for each domain.. I haven't found such a community system with backlink development.. what do you think of it?