The benefit of running a PPC campaign alongside an optimisation campaign is you are given that instant visibility you are wanting, whilst your optimisation is working in the background. You then have the option to reduce your AdWords campaign when you have the organic listings to counteract the loss in traffic. Although, many of our customers maintain the AdWords campaign so they are dominating that first page of Google.
The more you appear on the first page, the more real estate you own on the first page of Google which will make it difficult for your customers to miss you.