You should update quality article frequently and do SEO to find perfect key word. This is the best solution for your site.
Do you mean if your site is down like maintenance? If that's the case you can always use that time to write new content for your site. If you mean if your site has fallen in the serps. Try updating your page with optimized unique content. Keyword Rich (not stuffing) articles and find other methods to gain traffic to your website. Blog commenting, social media, paid advertising, etc... don't depend on just one source of traffic.
Well if mine falls, i guess the only thing i have to do is fix it by improving my on page and off page techniques.
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If you are talking about keyword ranking then I would like to target different keywords so I always rank for few of them. I also would like to have different sites for diversification of my income sources.