The words in subject lines that increase open rates most, on average, are

• upgrade (+65.7% compared with average open rate)
• just (+64.8%)
• content (+59%)
• go (+55.8%),
• wonderful (+55.1%)

The words that have the largest negative impact on open rates are

• miss (-4.6% compared with average open rate)
• deals (-4.4%)
• groovy (-4.3%)
• conditions (-4%), and Friday (-4%)

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