For one to five users you might try Hubspot or see the cool ways people have used Airtable as a CRM.

If Google adwords is working for you, why not keep working on that acquisition method? Do you have a Dribbble account? Could be a good source for new customers, too.

When looking for a logo, clients want to see your past work, hear recommendations from your customers, and know the pertinent details (how long will this take, what's the process)? I find most graphic designers make this all hard to find on their websites, so make sure you are optimized to answer your customer's main questions before they have to ask them.

If you don't have time for your own blog, there's nothing wrong with that, but perhaps you could write a guest post for another small business blog that gives tips on picking a designer, communicating your vision to a designer, what to expect when you want a new logo, etc.

Yes! I ran a silk-screen printing business when I was 15. It was a great learning experience.

Do you ever watch Shark Tank? This episode has all kid/teen entrepreneurs:
http://www.huffingtonpost.com/2014/03/12/shark-tank-kids-episode_n_4950983.html

Here's a Ted talk check out:
https://www.ted.com/talks/maya_penn_meet_a_young_entrepreneur_cartoonist_designer_activist

Remember, most adult entrepreneurs have no idea what they are doing! We try things, see what sticks, and learn from our mistakes.

[Deleted my answer! Misread the question.] Doh.

HelpScout, ZenDesk or Desk.com.

HelpScout (help desk software) would be a great start – less options but even when I ran a 6 person customer support team (with over 500 emails a day), we never needed the complex features of Desk.com.

Have one person create 'saved replies' to quickly answer your customers in a cohesive voice and with consistent responses. (However, encourage your entire team to inject some of their personality!) This seems like a huge task, but if they dig through their sent emails, it can be done pretty quickly.

Good luck!

Here are a few:

Shopify: First 14 days free, then a transaction fee
StoreEnvy: Completely free for your own private shop, but anything that is sold from their marketplace, they get 10%.
Etsy: $0.20 to list an item, 3.5% transaction fee.

When Etsy started, listing an items was free (just a very small transaction fee when an item sold). You want to get a big enough marketplace to attract buyers, so this is a good idea.

Perhaps you can think about adding optional features for buyers and sellers as an alternative revenue stream.

Check out CloudPeeps! Sort of like Clarity but specifically for social media + community managers: https://www.cloudpeeps.com