Climbing the Google Mountain

If you're trying to rank high for a competitive keyword, it's like climbing the Google mountain. If it's a brand new phrase, you can sometimes be the first to the top and establish a camp and keep everyone else off just by being there first. When the mountain's already been conquered long ago though, and people have settled in and got their feet under the table, generally you can't replace them. A large and significant part of the Google algo respects age. You can get links from everyone that the top site has got links from, but you'll probably never rank as high because you can't get links that are as old as the existing ones. Yours may well be a far better site, but Google search results will never reflect that unless you can not only persuade sites to link to you, but also to drop their links to the existing top-ranked sites. Your best bet is to go long-tail, do your related keyphrase research and build a whole load of new mountains. That way everyone who comes after you will find that you're the one at the top of the mountain they all have to beat.

There's an old wrestling maxim, "To beat the man you have to be the man".

To beat the man that's already got top SERPS, sometimes you'll find you have to build your own Google mountain.

Further, during the optimisation process it's to be expected that terms will plateau. While there remains obvious work to be done on the site in other areas which will benefit the site by making other terms more visible, the thing to do is to get that work done. Increasing the visibility of the site for related terms will improve the likelihood of it gaining links for those related terms which will enhance the reputation of the site overall causing it to rank higher against the competition, including for those terms that had hit a plateau earlier.