Amazon’s Prime Day continues to gain competition from rival retailers piggybacking on the annual event with their own sales. Ahead of this year’s Prime Day, RetailMeNot had forecast that this year’s sale would see competition from 250 retailers. Today, the firm upped this figure to over 300, saying it found that more retailers than earlier estimated have decided to run their own counter-sales.

As of 9 AM on the second day of Prime Day — Tuesday, July 16, 2019 — RetailMeNot says it has counted over 300 unique retailers running Prime Day-related offers. This is up from the 275 retailers it had uncovered yesterday afternoon, and up from the 250 it had forecast.

For comparison’s sake, Prime Day 2018 saw competition from 194 retailers; the year before that, just 119. And only 27 retailers ran counter sales back in 2016.

The rival sales come from retailers both large and small and are targeting online shoppers with aggressive deals, flash sales, free shipping offers, and other promotions. These sales extend across all categories and retailer segments, the report also notes.

Free shipping — which is one of Amazon Prime’s biggest draws — is a common offer from the Prime Day rival sales. Retailers are either lowering their free shipping minimums or touting free shipping “with no membership” needed, to counter Amazon’s plan to woo subscribers to join its free shipping service and perks program, Amazon Prime.

Many retailers are also using messaging that includes words and phrases that appeal to e-commerce deal hounds, like “Cyber” (13% of retailers used) or “Black Friday” — e.g. “Black Friday in July” — which 32% of retailers used. But even more are directly copying from Amazon, as 38% used the word “Prime” in their messages to consumers.

Some retailers even went for clever variations on the word “Prime” itself — like Joann Fabric’s “Primo Days,” for example. Meanwhile, ULTA’s deals on beauty primers were referenced as “up to 50% Off Primer Days” while West Elm noted several “Reasons to Love West Elm, (Primarily) Today.”

Already, the e-commerce market in the U.S. is feeling the impact from Amazon’s sale. According to Adobe, large retailers have already seen a 64% increase in their e-commerce revenue, compared with a typical Monday. It also predicts Prime Day 2019 will push total U.S. e-commerce sales to over $2 billion, when it all wraps.

Whether or not the sale is still paying off for Amazon as expected with all this new competition remains to be seen, however.