Two months ago, my sister and her longtime boyfriend got engaged (stay with me here--I promise this leads to something). I was so excited for them and my sister and I immediately dove headfirst into late night phone calls about her dress, floral arrangements, and of course, the venue.

I enthusiastically stepped into the role as her wedding planner because logistics are my thing. Plus, how hard could it be to organize a big love party?

Turns out that you could be the most spreadsheet-obsessed person and there will still be issues you could have never forecast. The problems I ran into had nothing to do with places or products not being right for us--it was that the vendors didn't seem to want to sell to me.

If you're a business owner or vendor, why would you not always believe that every customer that walks into the door wants to buy something from you? It's an opportunity to turn a momentary purchase into a lifelong customer or fan. Whether it's a two-dollar drink or a thousand-dollar couch--or in this case, tens of thousands of dollars into a wedding venue, there is one rookie mistake to avoid:

Never make any assumptions about your customer

There were multiple occasions in the past few months when I would hop on a call with a prospective vendor to ask about packages and pricing options and was met with a knife-stabbing,

"Oh, we have other packages as well, but you probably can't afford it."

In the five minutes we have been on the phone, how did you decide whether or not I had enough money to afford your services? These moments reminded me of other questionable moments I've walked into luxury stores only to have the sales reps eye me up and down, roll their eyes, and not offer the customary "hello" that they said to everyone who came in after me.

There is so much wrong with what these vendors are saying to me, but it comes down to this: making your customer feel like they can't afford something or that they aren't worthy of your product, even if they can and are, is a surefire way to lose a customer. What is the point of undermining someone who could make your business money? There is no point.

I thought that upselling was the sales technique--not down and degrade-selling.

Yes, while personas are extremely important to creating marketing speak for your company, it should not be the face you hold up to each person that wants to buy something from you. Personas are meant merely as a guide, not a discrimination guideline.

Step away from what your ideal customer sounds or looks like and take them at face value. If they've shown up at your doorstep, give them a good 'ol metaphorical hug and find out how you can make them a believer. In a day and age when customers can go anywhere, throw the discrimination aside and treat everyone equally.

At the end of the day, it's the one easy risk you can take that may land you with a lot more business and a much better response.