I've seen a few posts on here discouraging others from pursuing a career in sales as it relates to MBA admissions. In particular, some have argued sales doesn't look great at M7 or t15 programs (and recruiters who go there) because it has a low barrier to entry, it's not a desirable job function for top undergrads, doesn't sell one as being an intellectual powerhouse, is viewed as a solitary profession as opposed to team based, etc.
In fact, I saw someone saying it doesn't matter if you work at a brand name company as role is important - saying just because some works at JP Morgan doesn't mean they have a desirable MBA job if they work in the wrong job, such as a bank teller. To these people, "sales" is a similarly "low-prestige" profession to being a bank teller, even at a top company, and isn't a good feeder into top MBA programs.
However, my sales background didn't hinder me at all in my MBA application process. Remember that the top programs are focused on putting together diverse classes of high-performing professionals. Yes, bankers and consultants make up a portion of those classes every year but they're certainly not the only industries eligible for those top programs. (And the bankers and consultants are actually over-represented in the MBA applicant pool, often making it more challenging for them to differentiate themselves from the pack). My interviewers said I could bring a great element of diversity with a non-traditional pre-MBA career.
To be transparent, I worked in high-tech B2B sales at a top tech company (think Oracle, IBM, SAP, Google, Facebook, Salesforce, etc.), and had upward career trajectory with two promotions, which looks good at a f100 firm.
Breaking into tech sales at a top firm is difficult, and most of my sales co workers went to top undergrad programs (Cornell, Duke, Georgetown, UC Berkeley, USC, UCLA, UMich, UVA, Boston College, UNC Chapel Hill, UCSB etc.), had legit majors (UCB Haas, UCB Econ, USC Marshall, UVA Econ, UMich Ross, and one person from Duke mechanical engineering with a 3.82 GPA!, although there were a lot of high-GPA liberal arts people too), had business internships, and had decent grades (we had a hard 3.2 minimum GPA requirement, and most had a 3.5+ college GPA). We 1000+ applicants for maybe around 100 spots every six months, and people who went to non prestigious schools or state schools, who didn't get good grades, etc., got cut. I know a lot of fellow UCB people who got cut from the interview process.
Maybe sales in general doesn't have a high barrier to entry, but tech sales at a top brand-name famous f100 company definitely does. The products I sold (ERP, middleware) were very complex, and I had to learn a little bit of coding and spend quite a bit of time getting my technical knowledge up to par as a non-tech person. Due to this, what I was selling was intellectual stimulating. You have to have both book smarts (to understand and convey the complex tech products) and street smarts to pitch them to clients. The pay can be very high (80k+) for only 40 hours a week, so it was desirable for many fellow UC Berkeley grads (we had a TON of UCB people at my office, in fact most salespeople were from there and USC). Moreover, tech sales is very, very team based especially when you're dealing with strategic prospects (those with revenues exceed 2 billion/year).
I was always exceeding quota and was in the top 20-30% of my salesforce.
What helped in my interviews and essays was showing at how my role as an Account Executive showcase how I'd driven the strategy and vision for a business unit vs. simply being a great salesman. During my last promotion, I directly managed a sales team as "team lead." Overall, I had 3.5 years of experience at said top tech company at time of application, and 4.5 years of WE at time of matriculation into Wharton.
Interviewers said it was very impressive that not only did I get into a top tech firm right out of undergrad, that I had a few promotions along the way, which is difficult to accomplish at a f100 firm with all its red tape. Moreover, they praised my interviewing skills, saying not many people at top MBA programs have a sales background, and it'd be an asset to me since I'd have no problem in public speaking, making connections, building rapport with clients, etc.
I had other things going for me - I graduated UC Berkeley as a History major, had a 3.81 GPA, and got a 750 on the GMAT (50Q). Plus a few good ECs here and there. On the other hand, I was a straight white male who was 28 years old, on the older side.
I used my good academic stats, plus key stories from my WE to address and overcome the stereotypes some business people had on my profession, to show people I was smart and had both academic chops in addition to people skills, and I ultimately succeeded with it. WE, while the most important factor, is only part of your application, and your GMAT score and GPA (as well as undergrad institution) play a huge part. As does your ability to write a coherent story -- I tied in very carefully how doing demos and solving clients' business problems made me enjoying the consulting parts of my job, and why I wanted to do management consulting full-time. ECs can put you over the top.
While I didn't work at Goldman Sachs or Bain, or worked in IBD or consulting, I never felt my sales background was a hindrance in the MBA application process or while applying to consulting roles at my MBA program. Good soft skills always helps, and you can spin things in your favor. I wouldn't characterize working in tech-sales, at say Oracle, as non-blue chip for example. Oracle (along with Salesforce, IBM, Google, Microsoft), etc. is a brand-name company and tech sales/BD is a solid and lucrative field.
I was pulling in about $100k annually as a tech salesman prior to my MBA, for example, and the soft skills I gained from being in sales helped me immensely in building a network at my M7 program, securing the MBB interviews, being likable to others, rock all the behavioral interviews I ever did, become well-liked by peers who could give me references, and succeeded in recruitment (although you need the technical know how for the consulting case interviews of course).
While working as a used car salesman at a dealership probably won't look the best, if you work at a brand name company (top f100 firm), have a promotion or two, had some leadership experience, and were a top-performer, you can be very competitive for M7 or t16 MBA programs. For full disclosure, I got rejected from Harvard, Stanford, Tuck, and Sloan, but got into Wharton, Booth, Kellogg, and Columbia (I applied R1 for most of them). However, I did get interviews (ultimately denied) for Tuck and Sloan. Didn't use an admissions consultant, and I applied around four years ago.
My ultimate goal is to do a tech startup after cutting my teeth a few years here in MBB. To be honest, management consulting wasn't all that it was made out to be, and I'm doing it to pay off my loans before jumping into entrepreneurship. However the experience here has been fantastic and I love my peers.
But I don't regret starting out my professional life in sales, and it's been invaluable as a consultant -- I've been able to edge out compared to some of my peers who are very book smart but lack social skills. I was a complete nerd in college, and sales helped me refine my emotional intelligence, which is imperative in business. And many CEOs come out of a sales background (virtually every IBM CEO has a sales background), so that'll help me in entrepreneurship.
I think sales is devalued in "elite" circles to people's detriment and that's a shame. But if it's something you're interested in pursuing, go for it, and you can get into a top MBA program (M7 or T16) if you're overall package is good. If you feel being a salesman is a good fit you for, don't disavow it merely because someone said it won't look good or "prestigious" for MBA apps.