The vacuum cleaner has the dirt bag on the inside.
or
To prevent clients from being billed twice for essentially the same service.
or
They both look good hanging from a tree.
or
A gigolo only screws one person at a time.
or
A good start!
or
One's a spineless, poisonous blob. The other is a form of sea life.
or
A jury.
or
Hell, you need 250 just to lobby for the research grant.
or
A Doberman.
or
One in 3,000,000 has a chance of becoming a human being.
or