I ran multiple simulations for the same portfolio today, and the estimates are different for each. Why?

One of the following probably occurred between the time the simulations were generated, so the estimated clicks or revenue at various spend levels may have changed:

• The daily cost model was computed using the latest traffic data.
• The daily revenue model was computed using the latest revenue data. 
• AdLens synchronized with a search engine, social network, or display network and retrieved changes to campaign data (for example, an active bid unit was paused or a paused bid unit was reactivated).

Use the latest simulation because it is based on the most current data and account structure.