Serial Entrepreneur & Angel investor. CEO and founder @ Revieve. General Partner @ LandInChicago. Founder and COO @ RapidBlue Solutions (acquired by ShopperTrak in 2013). Mentor @ Techstars, Impact Engine & Healthbox. I've built, scaled and operated multiple technology businesses through which I've executed both direct and partnership-driven go-to-market models with successes and failures. I've secured multiple rounds of VC-funding ($1m+) both for my own businesses as well as participated in helping companies I've invested in. Realized high multiple investor returns (9x+). Product-focused. I've filed and retained significant IPR both in the US and Europe.
The first question is do you wish to stick to only Xmas Sweaters? If you do, there are several ways you can develop your business to a more year-round business without using a channel-approach (like partnering with year-round Christmas stores) but still sticking with your direct-to-consumer e-commerce site. Assuming you also don't want to start tempering too much with the production of the sweaters, you can simply create an additional line of shirts targeted for fall-sales, like "its never too early for Christmas" or "Wish Christmas was here already" -sweaters. You can use similar techniques to extend your season post-Christmas. Im more than happy to setup a phone call to discuss in more detail.
If you're an entrepreneur starting out, you CANNOT outsource sales and marketing. If you are not able to sell your own product, the business that YOU created, no one else will. Furthermore, if you haven't even tried selling yourself, how do you even begin to understand what the characteristics of the right sales people for the job are to make sure you hire the right people? You mentioned you had a full-time job and can't jump in yet because of financial reasons. That doesn't mean that you can't start selling your product, understanding why your customers are interested or not interested between the hours of 5PM to 9PM. Or 9PM to 2AM. Having a full-time job is not an excuse to outsource sales and marketing.
On top of what Jason explained, which are the basics for starting any business, based on understanding who your audience is, you need to figure out where they are? How do they get information on the topics you are hoping to consult them on right now? Who is providing that information? Why are they listening to those individuals right now? Only by answering those questions are you able to target your audience and reach through the noise that is being presented to them today.
First you need to develop a business model for your application. How are you going to make money, who is your customer, how much you believe you can charge per customer and what is the value they get from your application. Then you need to figure out how to acquire those customers. No one can give you a definite answer here, figuring out a business model, value proposition and customer acquisition strategy and executing on them are all crucial components every startup needs to figure out by themselves.
In addition to what Ryan mentioned, you have to remember that Amazon started from a very narrow niche. They did not start as the global e-commerce destination they are today, but rather from enabling people to buy books online. And only books. This gave book publishers and even bookstores with an additional channel through which to sell their products and consumers a new way to buy books. So there was both a great new, revenue-stream for sellers (and still is today) as well as a new, convenient way to buy for buyers (and still is today).
I think you're looking at this the wrong way. Your suggesting building a competitor for Teespring.com and focusing the features that Teespring doesn't have (or limits) with the assumption that those features are what is stopping Teespring's growth. What you should rather focus on is figuring out what is the most frustrating part of using a service like Teespring as seen by existing users and see if solving that problem has value. Building a pure copy with some added features is probably not a good idea.
From the outset you as the founder have to be doing the sales, or then find yourself a co-founder (which is not the same as a SaaS sales rep) to help you out on the business side of things. But unless you do the sales, you will never figure out what will work, which part of the value prop is resonating and therefore you will never find product/market fit. Hiring a sales rep too early (prior to you getting a few customers on your own), will simply result in their inability to sell your product which you will attribute to their failure as a sales rep when in fact the product's value proposition isn't yet clear enough for any customers to buy at scale. So close the first accounts first on your own or get a co-founder on board who can, but don't go out and hire a SaaS sales rep until you know what the product really should be. Once you do know, you can easily hire a few SaaS sales reps on low retainer + hefty commission.
Their staff. If you're talking about your average SME, there's great power in unleashing your employees as a marketing force (and Im not just talking about your marketing personnel). Everyone has a social network, both personal and professional, everyone has friends, connections, opinions that they share that could all be harnessed as a force for marketing the employers products and services.
If only it we're as easy as someone telling you exactly what to do and voilá, the customers would just appear. In reality very few startups actually fail because they can't put together a decent product and very many fail because no one ever hears that they exist. There are a great variety of different customer acquisition channels you can try. If you get one channel to work, you already have a good business. If you get more than one to work, you have a fantastic business. I'd recommend reading online about customer acquisition channels.
First of all, usually funding rounds are NOT used to pay back previous investors but rather insert cash into a growing company in order for that company to reach new scale. If you're accepting equity as part of your compensation, you're also accepting the risk that this equity can be worthless or potentially very valuable. The only way you will get liquidity from this equity is through an acquisition of the company where your shares are sold or by selling your private company shares to another individual prior to such liquidity event. There's no guarantee you can sell your equity or that it will be worth a set amount.