That is rite...optimiazation! Whether it is the way they think something is spelled or because they are going to fast while typing and add a few key stroikess in there somewhere, people while searching have tipos all the time. You want to capitalise on this by adding some of the most comon misstakes to your list of key words.
You want to look for missspellings the most. Use a good keyword finder and see what they pull up for words close to your keywords which have been searched quiete regularley. After you have tackled the mispellings, you move onto the areas where you think people would have the most slips with their qwerty...like hitting a f instead of a g or a z instead of an z ...I mean a.
Don't just ad this to your keywords though. YOu can register and redirect many domaine names to your IP adrress, too. It only costs $7-14 for a domain and is very worth it if you find many people trying to reach you fromn the other domains. THe bots love it when you do that.
Hear are a bunch of keywords an SEO company might try to work with to help convert traffic:
Search engin optimization
search engine optimiazation
search engine optimisation provider
search engine optimisation blogs
search engine optimisation stratergies
profesional search engine promotion
Hopefully these help you with figuring out what ou have to do for your sight.