There are disadvantages to transactional marketing. I would like to cover a few of them with a short case study of my own. Maybe these will ring true with some of your recent purchases as well.
I recently purchased a new vehicle. It is a beautiful new Chevy Avalanche. I purchased the vehicle from a local dealer. The transaction went really smooth and quick for me. I probably made some kind of record with the speed at which we went through the paperwork and I got to drive away in my new prize. I dealt with the owner of the dealership and it almost seemed like we connected on some level. It was a magical time for me. I had been building up to this moment for months and chose the exact vehicle before approaching the dealership.
Then it was over. All the joy and anticipation of the deal was gone. Now I had my prize and the excitement of the purchase faded quickly. Not to say that I don't love the truck, just that the build up to getting it was what was now missing.
The strangest part is that now I drive by the dealership and think: "Is there nothing more?" That is the biggest disadvantage with the transactional style of marketing. When the deal is over you lose all the benefit of the relationship you have build with your customer. All of the time and effort you spend building up to a sale, the effort it takes to get the customer to trust you and like you is gone. It is almost a wasted effort.
The repeat business is hampered by not keeping the relationship going. The next time the purchase is needed, you may be back in the long line of providers. The customer will go through the process of shopping around and you will be competing for their business again.