If your website (the domain name/URL) was indexed by Google at one time, but you can't find it anymore by directly searching for your URL for your website, your website has been banned by Google.
Things that could get your website banned:
Hidden Text: blending a series of keywords with your background color. Users won't see a difference but Google reads those keywords
Alt image tag spamming: Adding series of keywords in your image alt tag description. (e.g. img src="image.jpg" alt="spam spam spam spam spam spam" ) The purpose of an alt image tag is if a user visits your website and the graphic will not load, text will appear instead of graphic.
Meta Tag spamming: Spamming keywords in your META tag. (e.g. META NAME="KEYWORDS" CONTENT="SPAM, spam, SPAM, SPAM, spam") Google penalizes this! Avoid it.
Title Tag spamming: Spamming keywords in your Title tag.
If you are paying someone to optimize your website for you, be aware of the above! These are tricks that people use which risk their website getting banned!
