Who do you have the better relationship with? If you know the marketing director, then by all means go for it directly.

If you go through the agency, just make sure they have buy in and will be a champion of the idea. If not, then they may not be able to push it through anyway.

You don't have a marketing idea you have a joint venture proposition.
If you have an advertising infrastructure (your product), then you would approach them through through their marketing agency, because that is a logistics issue not big picture thinking/strategy.
If you have a complimentary product you are selling and thought of a clever way to leverage other company's budget and brand to sell more you have a joint venture, you would go through the executive leadership in that company most likely.
If you are a single person with only an idea and no tangible measurable data to back your theories, you would be better off pitching the agency and hope they implement it. Typically an agency who has a contract for a campaign can deliver ads in any way as long as it remains true to the original intent and does not affect budget. At least that how our team did it in the past.

Also, you don't have a strategy, what you have are ideas or goals. Strategy gets thrown around so easily it has almost lost its meaning.

Work with the big brand, but get an NDA signed first.

Bootstrap when possible and reasonable. Read "How To Get Rich" by Felix Dennis. Or better yet just remember the camel's nose in the tent story.

However, sometimes you just need to make a deal.

Listen, in any business you have to take some chances and some risks. Make sure you don't need a license and go for it. Remember, timid business people have skinny kids. Paraphrased from Zig Ziglar.

I am not trying to sell you on calling me. Really, I am pretty busy with my businesses and consulting. However, I need more info before I could have a greater impact in helping you.

Ask, Ask, Ask, then Ask again.

Bonus:
Here is $10,000 worth of information for free and in a nutshell.

Concentrate on the 3 M's. There are actually 7, but 3 will do for now. These are Market, Message, and Media. They come in that order.

Who is your target market (customer, clients, buyers, users, etc.)?
Tailor your laser focused message for this target market.
What is the best media mix to get your message to that market?

Here's what you do...first, make it an offer that is so incredible that they cannot resist. Secondly, do all the work for them. Make it so easy to make the purchase now that they can do it virtually without effort. Thirdly, give them an incentive to act right now. Fourthly, offer an almost unbelievable guarantee. Fifth, offer a bonus for acting now. There are many other incredible steps, but these steps should help the novice to the professional sell anything.

Whether you are selling B2B or B2C, you have to focus on selling to only one person. You can actually sell to one person at a time while selling to millions at a time. They are one and the same. Don't get off track, what we call digital marketing selling is just selling in print. And that has not changed since Cluade Hopkins wrote "Scientific Advertising." Really long before he wrote the book.

The secret to success: I have had the pleasure of knowing and working with some of the biggest names in business, celebrities, actors, entrepreneurs, business people, and companies from startup to billion dollar operations. The number one reason for their success is doing what they know and love while doing it in new, creative, and innovative ways.

Ask, Ask, Ask. Have thick skin and learn from each "mistake." In a short while, the market will tell you what you need to do and who and what you need to ask. But get started now even if that just means asking a contact on LinkedIn.

While you are thinking, think big and think of something at least 1% better, newer, or different. And being cheaper is not a winning strategy.

Make decisions quickly and change decisions slowly..unless you are actually going off a cliff.

Remember these two 11 letter words...persistence and consistency. They are two of the most important tools ever invented.

Treat everybody you talk to and everybody you meet (including yourself) like each is your number one million dollar customer.

Best of luck,
Take massive action and never give up.
Michael

Michael Irvin, MBA, RN