Improving your Google rank to get to the first page can be difficult and time consuming depending on your niche. But it’s achievable in most cases. Knocking off the number 1 listing and taking over the spot is an entirely different animal. It can be damn near impossible unless you are willing to make some major changes to your content and sometimes your site structure. We can get your site to the top of google but it takes time and money. In most cases return on investment is more important than getting to the top of Google. I’ve seen cases where I have gotten people to the number 1 spot and because of the cost they still didn’t make the profit they expected.
Once you reach the top that doesn’t mean that you will stay there. It just means that you are a target now and everyone below you is gunning for you. In order to keep it you have to continue with optimization tactics got you there. Which in most cases means a lot of extra work consistently creating more engaging, SEO compliant content to keep people on your pages longer. Search relevance is important but making a profit is more important from my perspective. My suggestion is to always build an email list from online and offline contacts and market to those people because they will spend more time on your site than cold visitors. By concentrating on pleasing your customer base Google will automatically elevate your site to it’s proper position. Sometimes they will rank you for keywords that you didn’t even know could be useful to you.