If you aren't able to cover all the expenses for a coming event or need sponsorship that will help you raise funds, a suitable format of sponsorship letter will help you receive folks to bail you out financially. So as to write event sponsorship proposals, you need to be cautious with letter writing approach for the possible sponsors. Using your partners to publicize your webinar invitation to their internal database is an excellent means to acquire more visibility for the two companies, and they're incentivized to send out the invite as those who attend the webinar might develop into a customer, or offer up-sell opportunities for existing customers.