TSL Marketing is a marketing agency based in Maryland, founded in 1999 by David English as Technology Sales Leads.
The agency finds sales leads for managed IT providers, software companies and other technology businesses. TSL Marketing also builds websites and sets up HubSpot, a platform of marketing and sales software, for clients. David English leads the company as president.
HubSpot lists TSL Marketing as a Diamond partner and named the agency the winner of Best Client Ebook at HubSpot's 2015 INBOUND conference.
Not to be confused with The SilverLogic, a custom software developer in Boca Raton, Florida, that also goes by TSL, or TSL Media Group, a media and influencer marketing company in Singapore.
TSL Marketing
ConfirmedTSL Marketing's business development representatives make outbound calls to prospects, qualify them on budget, authority, need, timing and environment, and set up calls between qualified prospects and the client. The company also builds and cleans contact lists.
The agency runs lead generation for channel organizations, IT companies that sell through reseller partners, and for the partners themselves. The work uses inside sales, telemarketing, email and paid ads.
TSL Marketing sets up HubSpot and moves client data into the software from Salesforce, Microsoft Dynamics, Marketo, Pardot, ActiveCampaign and other systems. After setup, the agency handles administration, optimization, reporting, automation improvements, user training and revenue operations consulting.
The agency plans, writes, designs and builds websites, and runs Google and LinkedIn ad campaigns.
TSL Marketing's AI SEO service adds structured data to a client's pages and formats the client's content to be quoted by AI tools, to help the client's brand appear in AI search results.
Rates
$5,000
TSL Marketing's minimum project size.
$100 to $149
The range of TSL Marketing's hourly rates.
TSL Marketing serves managed IT and managed security providers, software-as-a-service companies, solutions providers, cloud service providers, global technology companies and AI companies.
HubSpot's partner directory carries 14 client reviews of TSL Marketing, all rated five stars and dated from December 2015 to February 2026. Six of those reviews describe the agency as part of the client's own marketing team.
Clients with published TSL Marketing case studies
25 calls
ASi Networks is a managed service provider focused on network services. For a Cisco campaign run by TD SYNNEX, a technology distributor, TSL Marketing spent eight months on outbound marketing for ASi, which led to 25 conference calls between ASi and leads.
339%
Live Oak, a managed service provider in Texas, began AI SEO work with TSL Marketing in March 2025. Live Oak's average website traffic rose 339%. Within eight months, the Live Oak website produced more than 100 marketing qualified leads.
300%
TSL Marketing ran an AI SEO program for Macedon, a consulting firm for Appian software and business process automation. Over the year before the case study, clicks from searches for "Appian consulting" grew 300%.
Figures are from TSL Marketing's own case studies. For FDM4, an enterprise software company, TSL Marketing made the ebook behind the agency's 2015 HubSpot award.
Clients who reviewed TSL Marketing on HubSpot's directory
DP Solutions in Columbia, Maryland, IT Authorities in Tampa, Pegasus Technology Solutions in Dallas and Clare Computer Solutions in California's Bay Area have reviewed the agency. DP Solutions wrote in 2020 that TSL Marketing helped DP Solutions bring in nearly $1.8 million in contract revenue that year.
Burwood Group reviewed TSL Marketing's telemarketing and digital marketing work in 2021.
Studient, which sells AI-powered personalized learning for students, reviewed TSL Marketing's HubSpot work in 2026, from website development to AI integrations.
QC Supply reviewed TSL Marketing's work in 2025 on a website integration and training for the QC Supply sales team.
Sources
HubSpot's partner directory lists TSL Marketing in the Diamond tier, the fourth of five tiers in a partner program that ranks partners on points for deals and for servicing customers.
The directory also lists one accreditation for TSL Marketing, in data migration, a credential HubSpot gives only to partners at Platinum or above that show the expertise and practical experience to serve customers with complex technical and business needs.
At the partner awards of HubSpot's 2015 INBOUND conference, HubSpot named TSL Marketing the winner of Best Client Ebook.
DemandGen Report, a publication on aligning sales and marketing teams, recognized TSL Marketing's content marketing program at the publication's first Killer Content Awards, held in New York in April 2012.
Not found
HubSpot's directory lists only the Data Migration accreditation for TSL Marketing.
Figures differ
The company's pages give 12 or more, 14, more than 14 and 15 years.
Cannot be checked
HubSpot's directory lists 22 kinds of certification held by the agency's staff and gives no total.
Not found
No outside source counts TSL Marketing's managed IT clients or the pipeline the agency built.
Cannot be checked
No outside source gives the figure.
Sources
1999
David English founded the company as Technology Sales Leads, a lead generation firm for technology companies.
2005
The company began supporting Asia.
2007 to 2008
The company's website changed from the name Technology Sales Leads to TSL Marketing between December 2007 and January 2008.
2026
In March, TSL Marketing announced reaching the Diamond tier of HubSpot's partner program.
Office
6030 Marshalee DriveElkridge, Maryland
TSL Marketing's office is at 6030 Marshalee Drive in Elkridge, Maryland, the address on HubSpot's directory, on LinkedIn and in the company's website footer.
Clutch gives a headquarters at 8840 Stanford Boulevard in Columbia, Maryland, where the company also names a central office.
TSL Marketing's office in Pune is the hub for much of the company's global marketing work.
The company offers French-language support from Montreal and has a regional office in Singapore.
264 LinkedIn members list TSL Marketing as their employer. The company-size ranges on TSL Marketing's LinkedIn and Clutch profiles are 201 to 500 and 50 to 249 employees.
David English is president, and Brian Shilling is chief growth officer.
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