"Oh, [tech research company] must have a chart on that!". Many startup pitch decks features charts, forecasts, and quotes by Gartner, IDC, Forrester, and others to back up their market claims. Here is how a potential investor looks at these charts:

• Every deck they have seen over the past 10 years probably includes a $1b market forecast by one of these. Most of these companies are not $1b businesses.
• These research agencies do a reasonable job at mapping out what people are spending today on technology, forecasts are based on this picture of today, where an analyst applies different growth rates in an Excel sheet to get to a number that is 3 years out. It is an extrapolation of market trends, not a thorough research about how IT could change fundamentally
• Research relies on a categorization of the IT market with ambiguous names, it is never clear what is included, excluded, where a new technology fits, whether markets are double counted
• Overall IT spend grows at a steady pace, that's how corporate IT budgets work. So a revolutionary new technology cannibalizes investments in other technologies. Research reports hardly ever show sharp drops in the size of market segments. Rather, when a new technology emerges, people relabel, redefine the market segments to reflect the new reality. So again, not a helpful basis to forecast the future.
• The quotes in the research report are loaded with jargon, but most importantly, all sound the same. A product manager might be really excited that a Gartner quote includes "it will definitely think about considering making my IT infrastructure more scalable next year by investigating [technology X]", but for an investor this sounds all familiarly vague. 

So how to use this type of information? Treat it as just another data point, but don't make your entire pitch dependent on it.

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