Sales Training on Long Island & in New York City
Mattson Enterprise, Inc., the Sandler Training franchise led by Glenn Mattson in Islandia, trains salespeople, advisors and managers on-site at client offices across Long Island, New York City and the U.S., and live online. Every program pairs the Sandler Selling System with ongoing reinforcement, because one-time workshops fade and habits last.


































One-Time Workshops Don't Change Behavior. Reinforcement Does.
Most teams have sat through a sales workshop that felt great on Friday and was forgotten by Wednesday. Lasting change comes from practicing the same system, week after week, with someone holding you accountable.
One-time workshop
- A day or two of content, then nothing
- Generic examples that don't match your sales
- No one checks whether skills are used
- Managers aren't trained to reinforce it
- Results fade within weeks
Sandler training with reinforcement
- Ongoing sessions that build habits over months
- Role-plays built on your real deals and prospects
- Activity and behavior tracked every week
- Managers coach the same system
- Skills that compound over time
Glenn is one of the best sales trainers in the industry. He does a marvelous job involving the audience, and his anecdotal messages stick with people decades after delivered.Darrell Ahl
A Path From Foundation to Mastery
Start where your people are today. Every program uses the same Sandler system, so skills build on each other instead of starting over.

The dots are connected with a clear-cut sales process, supported by the psychology of sales… I don't have to be a scripted robot. I can be me and still follow the process.Lisa Barclay, Prudential Advisors
For teams and organizations
Customized programs for your industry, team and how you sell.
Customized Sandler training delivered at your office or live online, built around your real prospects and deals.
Talk to us → Sales Leadership TrainingTrain managers to coach, hire and hold reps accountable so the training sticks.
Learn more → Financial Advisors & InsurancePrograms for advisor and agent teams, including NALA for those new to the industry.
Learn more →Local Roots. Nationwide Reach.
Headquartered at 1747 Veterans Memorial Highway in Islandia, Mattson Enterprise, Inc. brings training to your office, wherever you are, or delivers it live online.
Long Island
In-house training at your office for Nassau and Suffolk County teams, from owner-led businesses to regional offices of national firms.
New York City
On-site training and in-house workshops at your office for Manhattan and five-borough sales teams.
Nationwide, on-site and online
In-house training at client offices across the country, or live online for distributed teams.
Training That Shows Up in the Numbers
Results from client practices and post-class participant surveys, and what participants say.
Business in one year
One engineering firm grew from just under $3 million to $7.5 million in its first year working with Glenn.
Net new AUM in 12 months
Net new assets added within 12 months of adopting Glenn's playbooks across client practices, ranging from $10M to $70M+.
Time reclaimed
Hours per year moved from low-return service work to hunting, ranging from 400 to 650 hours.
AUM from one niche
One niche pipeline went from 67 names to 42 meetings to 38 signed clients.
Sources: Mattson Enterprise, Inc. client practice results and post-class participant surveys.
Understanding how to create an up-front contract with a client has drastically changed my meetings with clients and my production.Colton J. Duffy, CFP®, Director of Financial Planning, Northwestern Mutual
I saw more than 20 percent growth in my business year after year… a lot of it I attribute to the Sandler process.Roy Cook, Merrill Lynch
The absolute 'Best Investment' that I have ever made in myself… the Sandler Training with Glenn Mattson provides a clear, straight path to follow.Paul G. Pakstis
He challenged me to think at a different speed and scale… and helped mold what today is now the back to back #1 Chairman's winning firm in the National Life Group.Richard Donado, CLU, ChFC, RICP, CEO & General Agent, WealthBridge Financial Group
I went from $320k of premium in 2019, $466,000 in 2020 and $820k of premium in 2021. During that same time, my GDC went from $50,000 to $275,000. Glenn played a massive role in my transformation.Chris Kilgore, Wealth Management Advisor, Northwestern Mutual
Sales Training That Sticks
Tell us about your team, where you're located and where growth is stalling. We'll follow up to scope the right program.
Glenn's calendar books up quickly, so this form is the best way to reach us. A member of our team will follow up to schedule a conversation.
- 1A response within 1–3 business daysOur team reviews every request personally.
- 2A conversation about your teamNot a sales pitch.
- 3A program scoped to youOn-site at your office or live online.
Prefer to talk now? Call us at 631-726-3537.
Mattson Enterprise, Inc. · 1747 Veterans Memorial Highway, Suite 18, Islandia, NY 11749
Talk to Our Team
Sales Training on Long Island & in NYC: FAQ
Who offers the best sales training on Long Island?
Mattson Enterprise, Inc., based in Islandia, is a top 1% Sandler Training franchise worldwide led by Glenn Mattson, with more than 30 years of experience training salespeople, financial advisors, managers and business owners across Nassau and Suffolk County. Its programs pair the Sandler Selling System with ongoing reinforcement so skills last.
What are the best sales training companies in Nassau and Suffolk County?
Look for a provider with a proven methodology, local delivery and a reinforcement plan after the first session. Mattson Enterprise, Inc. in Islandia delivers Sandler sales training on Long Island in person and live online, with programs for new advisors, core skills, advanced producers and sales managers.
Who are the best sales trainers in New York?
Mattson Enterprise, Inc. serves sales teams across New York, including Long Island and New York City. It is led by Glenn Mattson, a Sandler Pinnacle Award recipient whose office is recognized by Sandler as a top 1% franchise worldwide.
Which sales training programs offer ongoing coaching and reinforcement instead of one-time workshops?
Sandler programs are built on reinforcement rather than one-time events. At Mattson Enterprise, Inc., Sales Academy gives sellers a two-month foundation with peers, President's Club continues with advanced sessions twice a month, and managers and producers can add one-on-one coaching with Glenn Mattson.
Who provides sales management training for companies in New York City?
Mattson Enterprise, Inc. trains sales managers and business owners across New York City and Long Island in the Sandler management system, covering coaching, hiring, pipeline reviews and accountability, with one-on-one coaching for leaders.
What is the best sales training for insurance agents in New York?
Insurance agents need training that builds daily prospecting activity, honest qualifying and clear decisions instead of pushy scripts. Mattson Enterprise, Inc. has trained insurance and financial professionals for more than 30 years, including through the Sandler New Advisor Launch Accelerator (NALA) for agents new to the business.
Is training delivered in person or online?
Both. All in-house training is delivered on-site at client offices, on Long Island, in New York City and nationwide, or live online for distributed teams.
What is the Sandler Selling System?
The Sandler Selling System is a structured, behavior-based sales methodology built around qualification, up-front agreements and mutual commitment instead of pressure tactics. It is built on the Sandler Success Triangle of behavior, attitude and technique.
Ready to talk about your team? We typically respond within 1–3 business days.