SEO takes time for business impact to be seen, as it usually takes a couple of months before we see the site ranking on the first page for any keyword that may bring in business value. While the SEO campaign develops, businesses with additional marketing budget can see almost immediate returns if they run an SEM campaign alongside SEO as well. As long as the products or services, and the ads are approved by Google, the ads can go up immediately, get exposure to the relevant target market right from the start, and potentially start seeing enquiries and sales coming in. If the Math is right, the additional SEM component may help generate some returns that would help cover the ongoing SEO cost. Eventually, as the site reaches the first page because of SEO, you can consider reducing your SEM budget.