I remember in late 2008 getting calls from wise business owners who were looking to drive new business at the start of the Great Recession. They had slashed their marketing budgets, but still need to find new business and online marketing was their best strategy. Basically you can market online to most any segment with any amount of marketing dollars (large or small). Often times startup businesses, companies that are re-strategizing or business in a depressed market can revitalize their business by strategic investing in online advertising and marketing such as Adwords, Facebook ads or search engine optimization.
It can be relatively easy to get a return on investment (ROI) by placing a bunch of test ads, find which ads are working for you and then re-investing back into the ads that have the strongest returns. A/B testing with different ad copy, targeting different keywords for search engine optimizing (SEO) campaigns and social media marketing can be relatively inexpensive ways to find new business.
When should you start these campaigns. Depending on your category, now might be the right time. Some categories are more competitive so it takes more time to find results. For example, if I were an attorney and wanted to rank for 'Denver personal injury lawyer' I would want to start that SEO work now. It can take months to start ranking for competitive categories, so the sooner you start future proofing, the better off you will be.