"All projects experience changing requirements.  Traditional projects view this as bad.  Agile projects embrace it."  -- Steven Thomas, BBC

Kelley Hunsberger writes about embracing scope creep, rather than fight it in her article “Change is Good”, in PM Network.

According to Hunsberger, scope creep can create three key opportunities:

1. Clients can figure out exactly what they want - clients figure out what they really want through the process
2. The project team discovers a thing or two - the technical team is figuring out what works and what doesn't.
3. Flexibility pays off - the ability to react to something late in the cycle is a competitive advantage.

In my experience, this tends to be true, especially for knowledge work or where the work is not well known.  Change is a good thing, especially when it means acting on windows of opportunity, and delivering more value, in a timely way.  Customers tend to embrace the change when they are involved throughout the process.

My favorite point in the article is about shaping scope as you go -- "With every sprint or iteration in agile, you are adding more clarity to the project's scope and reacting to it.  But just because you are changing the scope of a project doesn't mean you are adding more scope to it."