Generally, the transfer of tangible personal property is the trigger for a sales tax event. In this case, it may be necessary to review the various aspects of a typical transaction to determine if any portion thereof would be subject to sales tax. However, generally speaking, receipts from the sale “Marketing”, "Media Placement Services" and "Web Site Networks" are not subject to State or local sales and compensating use taxes provided your organization does not sell or otherwise transfer any tangible personal property to its clients in conjunction with these activities or perform any services otherwise taxable under Section 1105(c) of the Tax Law in conjunction with these activities. (See, Advertising Agencies, Technical Services Bureau Memorandum, June 10, 1983, TSB-M-83(16)S.
For additional guidance, you may also want to refer to Publication 750, A Guide to Sales Tax in New York State http://www.tax.ny.gov/pdf/publications/sales/pub750.pdf.
I hope that you find this information useful.
Shawn Powell Joseph
Reference
TSB-A-97(43)s