When most people talk about local SEO, they are talking about how to rank well in Local Packs. The problem is that Local Packs are off the table for online-only businesses.
This doesn't mean that local search isn't an option though. If you extend local search to mean all search with a location-specific intent, it can be expanded to include PPC and organic search.
This presentation gives you five tactics to succeed in local search, even if your business doesn't have a physical premises.