Been down this route with my current company. Sorry if this answer is long winded, but I want to give a full description of why being a single co-founder worked for me personally. I am currently finishing up my first year in business and am only now in the process of bringing on a co-founder. There were some benefits and pitfalls to this approach, but looking back I would not have done it any differently and I couldn't be happier about the decision to proceed alone. I should note that a lot of this had to do with complete luck as I will explain below.

First, I am building a niche, taboo startup (helping ex-offenders through re-entry). When I first started many of my friends, and people I considered potential co-founders, found the idea a little too risky or crazy for their liking. Many didn't understand the market and were skeptical that a market even existed. I was not going to give up though and was bound and determined to get a business model built and launched, so I pressed forward. Bringing on a co-founder just to say you have a co-founder is a the perfect recipe for disaster in my opinion.

Out of luck I got accepted into an accelerator program for social impact startups. The overall value of the program is a blog post in itself, but the one enormous benefit that came from it was the connections within city government and other startups. It is through this that I ended up meeting my co-founder. We are still hashing out the exact details of our agreement, but our skill sets compliment each other and we get along good. He also understands the market, has experience in it, and knows the business side of building this type of business. I could not be happier for the way it worked out. The whole process has allowed me to essentially do a "co-founder dating" period without giving up equity or IP secrets, and it allowed each of us to work together and see how we got along before getting into a relationship.

Now to give you the flip side and why I believe this approach worked for me personally. I had a previous startup where I partnered with individuals I considered friends. We ended up having an ugly falling out over money and development of the product. The fallout was devastating personally and financially for me, and while I take a considerable amount of the blame for the initial fallout, their actions after the fallout are what made the situation even worse (they divulged company data, were highly vocal to potential customers and investors, etc..). They essentially made it impossible for me to succeed even if I wanted to. While I probably could have sued, I ultimately felt it was easier to lick my wounds and walk away. I also felt that suing would just take me down to their level, and wasn't worth the battle (no matter what side you are on, lawsuits are not pretty or fun).

Long story short, the experience made me extremely skeptical going into my new venture of who I would bring on as a co-founder. When you hear the horror stories of co-founder breakups or that they are one of the leading causes of potentially good ideas failing as a business, I can attest to the outcomes. Ironically, the only reason I had taken on co-founders in the first place was because of outside pressure from potential investors that I needed to have at least one other person. Investments we didn't even end up getting.

Having a co-founder has its benefits and pitfalls in my opinion. Nobody can deny that the right co-founder is the ultimate blessing. They are someone who is right there in the battle with you through the good and the bad. They are someone you can call at 4am with a whimsical idea and know they completely understand why you called and get equally excited. They are someone that is in the ring fighting with you 24 hours a day, 7 days a week. The problem arises though when one of you can no longer afford to stay in the ring and continue to fight. Whether that is due to financial or personal reasons is irrelevant. When the frustration from one side grows so much that communication between the parties diminishes or does not occur at all, the fallout will begin. Each party will begin to blame the other, regardless of who is at fault. When this starts to happen, how it is ultimately handled by both sides together will determine whether the business comes out intact or fails. Best advice I can say here is to have a neutral third-party that can mediate the fallout. This is probably why you see funded companies navigate co-founder breakups easier than un-funded companies. Good investors know breakups happen and are ready to step in and help you navigate that breakup. Without that third-party though it is difficult and the chances of making through successfully are not in your favor.

While the building of my current startup has taken a little longer without a co-founder, it gave me some advantages. First, I had no one to blame but myself if the business fails. This gave me great incentive to succeed. Second it allowed me to be in the fight without having to be in the ring. Meaning that I while I was determined to build a business, if at anytime I wanted to quit the decision was fully mine and I could walk away without losing friendships or future business partners. Finally, it is giving me an enormous advantage as I prepare to finally enter the ring with my new co-founder. I have a product developed, it works, and I have people using the service daily. I don't have to sell anyone on the idea or business. Is the business 100% or completely finished, absolutely not. But one of the biggest hurdles has been jumped and by bringing on the co-founder now, it is more like tag-team wrestling where I can hand off the product and let him go sell. This doesn't mean I don't have to do anything from here on, it just pulls an enormous amount of pressure off me. It gives me time now to focus on fixing bugs, adding new features, cleaning up rushed portions of code (don't deny it we all do it), etc...

I should note that there were a few key items that I think made a big difference for me along the way. First, while I lean towards being an introvert, I consider myself fairly good at networking and making connections. As I was flushing out my business model, I reached out to a lot of people in the industry and made some great connections along the way. I also applied to several accelerator programs. Two of the programs that I applied to, while I was not accepted, have gone above and beyond in helping me. From introductions to answering emails at 3am providing design input/advice for my website/product. Neither of these teams had to do this for me, yet they believed in me and my idea enough that they go out of their way to answer my emails directly and provide feedback. I also have a good core group of friends that I can ping ideas off of and support me, and while they may think I am crazy at times they are there for me if I need them. I don't think without these pieces that I would have (a) survived the first year by myself, (b) made it to where I am today with the product.

So to answer your original question, by all means go for it! The right person will come along, and when they do, you will know it immediately.