Unless you create a lot of content, probably not. The affiliate program is about creating content to be used in blogs, webinars, emails, etc.
If you're looking to refer clients you’re servicing, you should join the Solutions Partner Program. In these programs, you'll be teamed up with a rep who will help sell your client on HubSpot and you will be able to sell the client your services.
If you also create a lot of content and want to use your link in that content, then yes, you can also join the affiliate program.