Any update on resolving this issue? I am looking to create a custom field for number of years work experience using a range of years in each value.
In fact, this issue cannot be resolved with the Number of Employees standard field. Number of employees is an integer, so you can only store a number in it.
If you want to work with buckets, you will have to use a custom field of type string. If you do so, you will be able to store your buckets.
We use DemandBase to enrich our lead data (e.g., form submits). We just created custom fields (type: string) so that the standard ranges of data values can be stored (for both REVENUE and NO. OF EMPLOYEES) in Marketo (and then mapped these to the appropriate CRM fields).
It's a messy question with no easy answer, unfortunately—I ran into this exact same issue when using BrightTALK since they define number of employees in ranges, so I wound up just hiding the standard Num of Employees field in both Marketo and Salesforce, using that to store definite numbers when they were available (along with a workflow to fill a range picklist) and just put the picklist in all public/sales-facing areas.