you might buy
blue widgets
"blue widgets"
[blue widgets]
and blue widgets won't get a high enough CTR but the other two will stick. Can also use different tracking URLs for each since they are different keywords.
blue widgets
"blue widgets"
[blue widgets]What would "blue widgets" pick up that blue widgets missed?
blue widgets will cover all for both "blue widget" and [blue widgets]. Thus, blue widgets will not miss anything. However, [blue widgets] will be preferred whenever the phrase 'blue widgets' is searched provided all phrase KWs have the status. When 'free blue widgets' is searched, "blue widgets" will be picked it up. The phrase blue widgets will picked others such as 'blue and red widgets'.