Why cant you do both? Accept the offer from them, but if another offer comes in from another company, just set your start date a little after you start the job with the first one. Like month or so. It will be worth the experience and who knows .. maybe you learn enough about it that you will actually want to stay. The point is, you are barely starting your career. I recommend bouncing around as much as possible for a year or two.
I know this sounds like terrible advice and would expect many down votes, but hear me out. At the start of your career you will not only be looked down on for lack of experience, but will reasonably be taken advantage of. My philosophy is to turn this around and take advantage of the system.
I started out in a call center. The worst job ever, but it was a stepping stone. Used that job to impress someone at a local sign shop who hired me because of the job I had, not for how long I was there (key point here). Few months later, I ditched that job by using it to impress someone else to get a related job and that person was all too happy to poach an already trained person from a competitor. In less than a year, I was back at the call center job, knowing I would not stay there so I was a little bolder and assertive in my work. Surprise .. they made me a manger there. Added that to my resume. At my next interview less than a year later, I aced it. Again they didn't care how long I was at the call center. I had demonstrable experience that was key. I was hired.
Also note this: each time I would make a point to tell the interviewer not to contact my current employer for references, understandably, because they would find out I am looking for another job. Everyone respected that reasonable request. Less than 3 years later my next gig got me a $7K upgrade. I had that job less than a year, but used that time to make some professional, niche contacts with clients and I used those contacts to start my own business. As a result my income went up to $90K for the next 3 years and I had found my niche.
The market changed and my business went South and I applied for a job with no recent references (because I had been a business owner for the past 3 years and would never have a prospective employer contact my clients for any reason ~ but that's just me). Instead I showed my website, client contracts and deposit slips to prove I had a legit business. I got the job. In less than 2 years I traded up from that $70K job to a $95K job. Around that time I was playing various offers against each other to my advantage. Was it irritating to the prospective employers that I was playing them against each other? I didn't care. I declined one job offer during this period 3 times (each time they came back with a higher offer). After just 4 months at the $95K job, I re-contacted the person whose job offer I turned down 3 times only to finally accept an offer with them for $100K.
This is capitalism .. every job is just a stepping stone to a better one. Once you find your niche your references will become less important. References can be jerks. After all what does a reference want from you now that you left? What obligation do they have to you? None whatsoever. A business contact is different. Although they have no obligation to you, there is a special kind of relationship that exists there. And when they do contact you, they wont care how long you have your current job or what your references are. Also, your skills and experience that you can demonstrate should be able to stand on their own regardless of references.