There are some worthwhile points in there - hiring too many people too early is always a risk and underprepared telesales people can harm your brand - but also quite a few suspiciously specific figures and claims (I particularly like the "more than <i>34%</i> of the leads you purchase may be unusable" claim, but the assumption the enterprise salesperson isn't doing anything useful to generate business over the "6-18 months to ramp up" is probably the most dubious one).<p>The validity of most of the claims very much depends on the product, value proposition and industry: there are an awful lot of industries where finding apparently suitable contacts is the easy part, plenty of salespeople whose <i>strength</i> is the network and knowledge that allows them to identify the right prospects at the right time - whether they spend more than 20% of their time doing that or not - and plenty of startups where <i>knowing who your potential customers are</i> is the very last function that should be outsourced.
If you're not a native English speaker, like myself, knowing that "SDR" means "Sales Development Representative" actually turns this into quite the interesting read.