i'll start
try using this
[keyword] = only showed when they search exact keyword
ex. [sexcam] = then your add will be shown when they type in that exact keyword and your add will not appear when then look for free sexcam
"keyword" = could be somthing before or after that keyword
ex. "sexcam" = then your add will be shown when they type in that keyword also when they search for sexcam forum
...
tb