The three most important things to consider when trying to get your business in the top 3 positions of the Map Pack are relevance, proximity, and prominence.
Relevance has to do with making sure your business shows up on Google searches when it should. There are things you can do and you will have to consider to make sure you are sending all of the right signals to Google.
Making sure to choose the right local category selections in your listing and your citations will help Google understand what your business is about. You want to make sure that they all match accordingly. Make sure you business’s NAP’s (name, address, phone number) are 100% the same everywhere you are listed.
Optimizing your sites content and metatags to make sure they are relevant with all of your listings and citations is very important and will go a long ways in helping you rank well for the keywords you want to rank for.
A sneaky ranking factor that matters now more than ever is the proximity of the searcher to your business. Generally speaking, the closer the searcher is to your business, the more likely it is that that searcher will get your business in their search results. But there are a few things you can do to let Google know you are, and should be, listed all around your city (or wherever it is you want to rank).
Content on your site about your locale helps with proximity searches. If you want to rank for search terms in London, add content on your site, blogs and other social networks about London. And in that content, insert driving directions (using Google's embedded iFrame code) either to or from “places of interest” to your place of business.
Do this for every location you are trying to rank for to improve your proximity rankings.
Google wants to rank businesses that are not only relevant, but they want to rank the most prominent, well-known and reviewed businesses as well. To increase your prominence score in Google’s eye, continue working on getting great reviews and continue picking up citations and links from places Google values as authoritative.
Remember, Google is gathering information about your business from across the web on a constant basis. The more positive information it gets, the higher the likelihood they will be to rank your business. Obviously this won’t (and shouldn’t) happen overnight, but as long as you are working on all of the things listed above in this article, you will eventually see results.