It is highly recommended that Single Table Dedupe be run on Leads, Contacts and Accounts to clean up any duplicates before running Lead Conversion. This will avoid added complexity in evaluating matches due to duplicates within each object and minimize the number of records returned in the result grid.
Please test your conversion scenarios thoroughly before converting a large number of Leads, as there is NO automatic "undo"/"rollback" option and NO restore files are created.
If you have a Salesforce sandbox, we recommend that you test in this environment first before converting your production data.
It is also highly recommended that a full backup of the database be taken before performing a large scale conversion.
It is highly recommended to have multiple match steps from Rigid to Loose to evaluate potential duplicates between objects.
Be cautious of your Loose scenario! If your Loose scenario is "too" loose, it will require a lot of manual review of this match step in the results grid to determine if the records are "true" matches.
