This is probably one of our all-time favorite questions! Improving PageRank to where you now rank for search terms which you previously did not will take time to do it correctly. The good news is, that you should see continuous improvement from where you started.
A lot depends on your industry, the strength of your competitors, how long they have been online and how long you have been online.
Remember, that Google is like a librarian and wants to make a valid recommendation. Although you may be doing everything right, a competitor who has been online for a few years longer than you and doing it all right as well is going to be a formidable foe to unseat.
The same hold true for particular crowded search terms. For example, personal injury lawyer, in almost ANY demographic area can be extremely difficult to achieve a suitable ranking. Your Implementation Specialist will inform you of any challenges which are unique to your particular industry or territory.
Occasionally, you may want to supplement your organic search results with PPC (pay-per-click) campaigns in order to remain competitive among entrenched players.
The main thing to remember, is that the Internet provides a pretty level playing field where almost any company can form a strategy to rank well on search engine result pages (SERP) in a reasonable amount of time.