Sam Chotiner, Strategy Director at McCann, gave away advice every consulting partner should read, remember, and embrace in their day-to-day work:
"Spend way too much time trying to find ways to be helpful to everyone around you. Just remember, everyone else in the room gets to choose if you are invited back."
I don't have extensive data to back up what I'm about to say. But based on my work and conversations with +100 consulting partners, being helpful is the trait that most strongly correlates with a higher sales performance.
Helpful consultants are not only the ones who bring in more new clients but also those who are best at retaining and growing current accounts. They say yes to things, even if it’s not their "job" or responsibility.
Don’t wait for opportunities to come to you. Proactively look for an occasion to help where you can. A consultative conversation, workshop, or small project can always become bigger over time.
Remember the power of smaller transactions in consulting. All of these small things will earn you trust, and make it more likely that they'll hire you at some point in the future. Worst-case scenario, it improves your relationships and reputation.
You can never lose by being helpful.