Speaking from the other side (I've been a marketer for decades), there are as many different marketing strategies as there are practically marketers. Some do no research at all. Others dive into it. If someone pitches you a product/service that is a bad match, it is the former. And you can also tell this by how much of a form letter it is. The more they show they clearly know you and/or your channel in their contact email, the more they're likely a good match and am actually interested in teaming up with you.
When advising advertisers about which YouTube channel to promote on, what ranks highly with me is if the YouTuber has made a video talking about what sponsors, if any, they're seeking. I think a lot of the Internet is over the "you sold out" as far as YouTubers taking on sponsors but it is always good to clarify that at the beginning of such a video. Then talk about your channel's demographics. Then talk about what YOU think would be a good match and SPECIFICALLY what you're comfortable doing. Don't be vague. Keep it professional. This video isn't for your viewers but potential sponsors. Make it for just them. Keep it concise and to the point. One of the best one of these videos I've seen was only 28 seconds long. If it is longer than five minutes, you're need to cut out the hot air and slim it down. Two minutes should be enough. Then when any advertiser contacts you, send them the link to this video as PART of your reply. Keep it updated and when you do an update, delete the old one so there is less confusion.
As for pitching advertisers, I wouldn't recommend it. Instead pitch advertising agencies. Simply make a video pitch. No, it isn't the same as the one I just described above. This video is not public so they will need to click on a link to see it. It is specifically for ad agencies and directly addresses them as such in the video. Don't get wacky or cute. The more professional you act in it, the better. If you're not comfortable in a business suit, you should at least wear corporate casual in the video. Start the video off by BRIEFLY talking about your channel, its demographics, and then talk about what type of businesses your channel can help. Then explain why you think that. Then tell what you're willing to do for an advertiser and for how much. I would recommend suggesting you give discounts if the advertiser is willing to promote your channel to their customers. If you're open to barters, say so. Always say you're willing to consider "creative deals". If you're cool with ad agency kickbacks, tell what "consultant fees" you're willing to pay for each deal they land for you. Keep it concise. Not a single wasted second. End strong.
Lastly, I would recommend you pitch your viewers. Ask them for help in getting you sponsorships. Tell what you're open to. Business owners, managers, and executives watch videos as much as anyone else. Not to mention their subordinates, wives and children. They might just need a nudge from you to contact you about an ad deal. You do not need to get into specifics. Keep it general and light. Slap it at the end of your video once in a while. A canned little pitch.
