Wild ass guesses (WAG) are really not techniques per se. They are, well, just wild ass guesses. They:

• Ask you to estimate how many units you will sell (or customers you will have) each month (or year).
• Educated third parties will not believe WAGs. However, a WAG may be all you have when you create your first financial plan. I highly recommend that you replace the WAG with something more reasonable before you show your financial plan to anybody else!

Many WAG approaches exist; for example:

• Predict number of units sold per month (or year)
• Predict number of customers you will have per month (or year)
• Predict how much revenue you will generate per month (or year) – the WAGgiest of the WAGs.

Contrast these with bottom-up and top-down techniques for the same purpose.

Related Questions:

What are top-down techniques?

What are bottom-up techniques?